• Aldnoah.Zero: United Earth Headquarters is pretty big: it has enough living space to house thousands of refugees, and when the Vers Empire invades in Episode 11, their attack helicopters and sky carriers are able to fly around the base at high speed with plenty of room to spare.
• Delicious in Dungeon: The titular dungeon was once the castle and surrounding town of the Golden Kingdom, a prosperous human civilization. One thousand years ago, a Mad Sorcerer sank the whole thing into the ground without a trace as part of a successful and misguided spell to make the inhabitants immortal after the sudden death of its king traumatized him. After it was rediscovered, when people realized the place was filled with abandoned treasure (even the walls were plated with gold), not to mention the prophecy that the one who defeated the Mad Sorcerer would inherit the whole kingdom, it set off a Dungeon Crawling craze.
• Dragon Ball Z: Bojack Unbound: The final arena where Bojack is fought is an expansive Victorian-era city built underneath the island where the tournament takes place.
• Gintama: Yoshiwara is an underground Red-Light District with its own laws separate from the Bakufu. It was originally an underground shipyard where the Bakufu built its ships, but Yoshiwara and its residents were moved down there after its original destruction during the Joi war.
• Made in Abyss: The Capital of the Unreturned in the sixth layer. Nobody knows how an entire city ended up down there, but the few reports that have made it to the surface describe it as a City of Gold. A small part of it, Iruburu, is still inhabited by former delvers who relinquished their humanity to the Abyss or became trapped by the city.
• The Mysterious Cities of Gold: The Morlock-like Olmecs dwell in underground cities.
• Noein: The populace of La'Cryma is forced to live in a large underground city due to constant attacks on the surface by Shangri'La.
• One-Punch Man: The Monsters Association have built their base in one of these below City Z. It is a sprawling underground network complete with tunnels, secret labs, gold mines, even plumbing. It is revealed that this was initially created by the Underground King and his army who tried to invade the surface at the beginning of the series... only to be eradicated by a single punch from Saitama.
• Queen Millennia, another Leiji Matsumoto anime: The aliens infiltrating Earth set up underground cities with fake skies to survive the coming apocalypse, with one of the shelters taking the 1980 style and others similarly showing the time periods they are from. A lot of Tokyo's residential buildings are also designed to move underground and save "the better parts" of the human population, which turn out to be spaceships that nobody would notice.
• Sakugan: Most people are living in underground cities that are connected throughout various landscapes beneath the surface.
• Sgt. Frog: "Side 6" (named after "Mobile Suit Gundam'''s space colony) is an underground city that functions as home and refuge for all alien immigrants on Earth. Apart from being underground, it looks exactly like any other street in Tokyo, with Expies of known locations like Akihabara.
• Space Battleship Yamato: With Earth's surface being uninhabitable due to constant bombardment and the resulting radiation, humans are forced to live in these at the start of the series. The Yamato has no time to lose, since if they're not gonna bring the radiation scrubbers back in one year, humankind is toast, since the radiation keep on creeping further and further into the shelters.
• Tengen Toppa Gurren Lagann: At the start, humanity is confined to a series of relatively small underground settlements. Anyone who dares to reach the surface is soon hunted down by Humongous Mecha-driving Beastmen.
• Texhnolyze: The city of Lux is underground. The ancestors of its inhabitants were banished there.
• Twilight Star Sui and Neri: District 7 is an underground city where most of its residents are animals.
• Uzumaki features an example that seems to fall into type three, although its origins are cloaked in impenetrable darkness. There's an enormous, spiral shaped Genius Loci buried under Kurozu-cho that appears to be the source of the town's "curse".

• Big Finish Doctor Who: Spare Parts, which tells the origin story of the Cyberman race, takes place in the last city on the Counter-Earth named Mondas, which has been placed underground to protect its inhabitants from the extreme cold outside.

• Blake and Mortimer: The people from Atlantis have moved their whole empire underground after their continent was sunk. They are installed in a set of gargantuan caves, large enough to contain their capital city, a sea (complete with storms), and various outposts.
• The DCU:
  • Action Comics #412: "Secrets of the First Metropolis": Superman discovers the existence of an entire underground city beneath Metropolis.
  • Detective Comics: In the "Shadows of the Bat" storyline, the Party Crashers, a gang with Joker tech, are based in an underground city beneath Gotham.
  • Legion of Super-Heroes: "The Unknown Legionnaire": While exploring the Protean homeworld, the Legion discovers a large underground ghost city, lit by artificial suns, and built by an alien race known as the Llorn when climatic change rendered the planet's surface inhabitable.
  • Seven Soldiers of Victory (2005): Limbo Town exists somewhere deep beneath Manhattan. Its inhabitants are the descendants of The Lost Colony of Roanoke, who abandoned the colony in shame after most of their women were raped by Melmoth and gave birth to half-Sheeda children.
  • Shazam!: In The Marvel Family #56 "The World's Mightiest Project", following a distress call, the Marvels discover a vast city deep down in the center of Earth. Captain Marvel guesses it must be inhabited by millions of people.
  • Supergirl:
    • In Action Comics #272 "The Second Supergirl", Kara visits an alien planet called Terra and discovers its center is inhabited by a humanoid civilization.
    • The Untold Story of Argo City reveals that the forbidden caves of the Kryptonian city of Kandor were dug by an ancient race long before the city was built on the surface. Kandorians are forbidden from exploring the caverns because they were booby-trapped to protect veins and caches of valuable and rare minerals.
  • Wonder Woman (1942): Queen Clea's Venturia and Queen Eeras' Aurania are both said to be Atlantean outposts but, rather than being underwater, in their first appearances they are underneath the ocean in an enormous dry cavern.
• Marvel Universe:
  • There is a sunken Atlantean city whose inhabitants age instantly when exposed to the surface's atmosphere for some reason.
  • Friendly Neighborhood Spider-Man: The 2019 series introduced another subterranean city to the Marvel Universe. Directly beneath New York City, accessible by giant elevator, is an identical city known as Under York. Inhabited by super strong orange people, they have a longstanding truce set up with the governing offices of New York, with contemporary Mayor Wilson Fisk acting familiar with its leader and their agreement.
• Robyn Hood: Outlaw: Tatter introduces the on-the-run Robyn to a hidden undercity beneath New York that is home to various supernatural creatures and other outcasts.
• The Savage Dragon: Chicago apparently was built over the ruins of an older city, now buried and inhabited only by superfreaks.
• Star Wars:
  • Star Wars (Marvel 1977):
    • "World of Fire": Xenoarchaeologists find an underground city under their dig site and decide to break through the still-functioning energy barrier put around it. This stirs up the xenophobic, paranoid security system, which kills them all, then people landing on the world to investigate, then ships flying in orbit overhead...
    • "The Darker": R2, C-3PO, Chewbacca and a gaggle of Hoojibs stumble across the ruins of an ancient cavern city in a particularly deep, isolated corner of the Hoojibs' cave system that they normall avoid. Avoid with good reason, as it turns out, because an ancient, deeply malevolent entity has been lurking in the ruins for millennia.
  • Tales of the Jedi: The Twi'lek cities on Ryloth are built within large caverns, in order to provide shelter from the heat storms that sweep in from the Tidally Locked Planet's dayside.

• The Twilight Empire: Robinson's War: The Sunken City of Valdor is an ancient, ruined city that now lies in the depths of a cavern in the wilderness.

• All For Luz: The Underdark, a town built directly beneath Bonesborough in secret, is roughly around the same size and layout of said town, the largest civilisation in the Boiling Isles, with facilities like a school, a library, and even its own museum. It also has a colosseum the size of Hexside.
• Dungeon Keeper Ami:
  • Ami's civilian complex, like the rest of her dungeon, is underground.
  • Dwarfs' cities are mainly underground, with the surface section being much smaller by comparison.
• A Hunter or Something: Beneath the Lunar Cry Mountains there are ruins of an ancient city. This surprises Ren and Jaune greatly when they discover it, as these mountains are so deep in grimm territory that no king has ever ruled there, so it's a complete mystery who built them. It's possible that the myth of Selene and Mouk originated in this city, as it has a tunnel that connects directly to Mouk's lair.

• Atlantis: The Lost Empire: Atlantis. Instead of simply being underwater, it was buried beneath the ocean floor, and is still inhabited.
• Flushed Away: The rats have created a miniature city built out of salvaged junk and flotsam in the sewers of England.
• Transformers One: The city of Iacon is depicted as such, having at least 50 sub-levels as well as several tunnels leading to Cybertron's core.

• Beneath the Planet of the Apes: There is a society of mutated bomb-worshiping humans with Psychic Powers living in the buried ruins of New York City. We learn a bit more about their history in the later Battle for the Planet of the Apes.
• Demolition Man: The part of the Los Angeles population that doesn't accept Doctor Cocteau's rule lives in an area dropped underground during the last major earthquake to hit the west coast which operates like a seperate city below the streets of Los Angeles. They survive by eating stolen food and rats.
• Doctor Strangelove: Invoked by the titular character, who claims that mines could be turned into giant underground shelters where chosen survivors of humanity could wait out the half-life of radiation from the Doomsday Machine. The novel version implies that this fails.
• The Fantastic Four: First Steps: Subterranea, a city state founded underground by Harvey Elder aka Mole Man, who doesn't like the people of the surface but makes an exception for Sue Storm. It comes into use in the climax when New York has to be evacuated since the gigantic Galactus is expected to plow through the city in search of baby Franklin. Sue's excellent diplomatic relations with Mole Man allows the inhabitants of New York to find refuge down there.
• Forbidden Planet: The Krell city is so large that it's a veritable Big Dumb Object. Standing in one of the huge ventilation shafts, Dr. Morbius says that the platform they're standing on runs for twenty miles in either direction, and there's 7800 levels above them. And there's 400 other shafts like it. The entire city is self-repairing and has been running without outside intervention for thousands of years.
• Genesis II: The Pax base is an underground. With lovely artwork and a nice decorating scheme.
• The Matrix: The only human city in existence, Zion, is hidden underground.
• Metropolis: The Worker's City is a utilitarian and gloomy place underneath the eponymous city of the movie. It becomes a symbolic of the worker's being an oppressed class, and is a plot point as the film's villains attempt to flood it.
• The Mole People is a 1956 adventure movie where two Adventure Archaeologists and one Load discover a buried Sumerian city where the people have mutated into albinos. The mole people themselves are a Slave Race of Beast Men who serve the Sumerians.
• Things to Come from 1936 is another early example. In an inversion of Metropolis; the underground city built on the site of Everytown is presented as a utiopian environment featuring clean filtered air and big-screen televisions. There is an extended Hard-Work Montage of the excavation and construction that shows off then-new techniques for filming miniature props and compositing them with human actors.
• The Wild World of Batwoman: The perpetually-captive Batgirl is taken by her guard to a vast underground city which is described as being around for thousands of years. The set itself was originally used for The Mole People.
  Mike Nelson: You've got Mole People in my Batwoman!
  Tom Servo: You got Batwoman in my Mole People!

Examples by creator:

• In Richard Sharpe Shaver's sci-fi stories, the Earth is riddled with underground cities built by the ancient races of Titans and Atlans. The greatest of these was Tean City, their capital. Unfortunately, the cities stand largely silent now, most of them haunted only by the morlock-like degenerates known as deros. A few of the cavern-cities remain as strongholds of the more benevolent Proud Scholar Races like the Teros and snailmen, however.

Examples by work title:

• Abandoned: The Queen Necromancer's lair isn't some measly enclave. It contains an entire subterranean city, styled after skeletons and bones of course.
• Artemis Fowl: The fairies live in a large underground complex of cities and tunnels as their way of hiding from the "Mud Men" on the surface.
• Ascendance of a Bookworm: Haldenzel Castle sits on top of a massive subterrainean complex where the people of the province shelter for the winter, going unoccupied for the rest of the year. Even larger underground cities are said to exist in the duchy of Klassenberg.
• Bad Mermaids: Salmon City, a mermaid city off the coast of Greenland, consists mostly of pebble houses in a cave under the seabed. Its entrance is hidden by an old shipwreck.
• Bazil Broketail:
  • Tummuz Orgmeen is largely inside of a hollowed out mountain.
  • Padmasa's capitol is mostly subterranean, with the Master's chambers deep below ground.
• Bigfoot and Littlefoot: Boone's Sasquatch community lives in Whiddershins Cavern, which is a sizeable cave system big enough for them all to have made it various nooks and crannies into stores, a school, and a residential area.
• The Books of Ember are set in an apocalypse bunker type of city where their supplies and power source are failing.
• Bounders: The surface of the Tunnelers' home planet Gulaga is so cold and barren as to be practically uninhabitable. Most Tunnelers live in Gulagaven, a city that barely pokes above the surface and extends hundreds of kilometers underground. The city is terrifyingly unsafe by human standards, with narrow, slippery bridges and ledges extending across and around the enormous central chasm, but the Tunnelers are used to it.
• A Boy and His Dog features fundamentalists living underground in simulated Americana.
• The Buried Life: The city of Recoletta, hinted to have grown from an Apocalypse Bunker centuries before. A subversion from most examples of this trope in that it is in regular contact with the surface which is where it gets most of its food. Several other such cities are mentioned.
• In A Case Of Conscience by James Blish, most people on Earth live underground, a carryover from the nuclear shelters of the Twentieth Century. This leads to the occasional riot.
• The Caves of Steel: Due to resource shortages and overpopulation, Earth's population consolidated into enclosed cities, building underground tunnels to connect one Mega City to another. Earth humans circa 5,000 A.D. are almost universally agoraphobic, because they live in an environment of corridors and tunnels (the eponymous "Caves of Steel"). The Earth's surface is given over mostly to agriculture, taken care of by robots.
• The Chronicles of Dorsa: The small men turn out to live in a vast one named Xochitcyan which is big as the local human capitol, with most humans completely unaware that it even exists.
• The Chronicles of Narnia: Adventurers seeking to solve the kidnapping of Caspian's son discover a previously unknown subterranean civilization of the Inhuman Borough type. It turns out the local inhabitants are slaves captured from an even deeper cavern biome.
• The eponymous City of City of No End is mostly above ground, but it has a cavernous underground region called the Depths which maintains the intricate life-support systems that everyone relies on. The humans who dwell there have been there so long that they've evolved an extremely pale skin that is sometimes even translucent enough to show all the blood vessels.
• The Coming Race concerns an underground Lost World of people whose ancestors fled below the surface to escape from floods thousands of years ago.
• Discworld: The dwarves live in vast, underground cities, and living underground is a part of their cultural beliefs. Vimes visits their capital in The Fifth Elephant, which is reached by elevator and holds a vast mine. He's somewhat displeased to find in Thud! that the dwarves in Ankh-Morpork are starting to build one in the network of buildings that has sunk below ground level, and extremely displeased to learn that their community leaders seem to think said underground city is outside his jurisdiction.
• In the pulp series Doomsday Warrior by Robert Syvertsen, hidden under the Rocky Mountains is Century City, which evolved from a road tunnel that was buried when the nukes went off; those trapped inside joined their resources and swore to liberate America even if it took a century. Thanks to good 'ole American ingenuity, Century City is more technologically advanced than the Soviet-occupied cities outside — exactly how this was achieved is left a bit vague.
• The first half of Dorothy and the Wizard in Oz is set underground, with the titular characters having to navigate through three cities to return to the surface. The first is the Land of the Mangaboos, which is a colorful city ruled by Plant People who are Always Chaotic Evil. The second is the Valley of Voe, which is populated by invisible people who have to eat a special fruit to protect themselves from invisible man-eating bears. The third is a wooden city where the Wooden Gargoyles reside.
• The Dresden Files: Chicago, as the protagonist puts it, is mostly built on Chicago. Like the Discworld example, the older bits, referred to as 'Undertown', are still accessible, but considering that trolls, vampires, some of The Fair Folk, wyrms, goblins and spirits of the earth live down there and bits of it were used for early testing of the Manhattan Project, even the powerful protagonist tries not to go down there unless he strictly has to.
• Dune (1965): Almost all of planet Ix's industries are built underground, leaving the surface to more agrarian pursuits. All the better to hide their pursuit of forbidden technologies.
• A Face Like Glass: The central setting, the city of Caverna, is located entirely underneath a mountain.
• First Light: Gracehope was built into a glacier.
• Foundation Series: During its peak, the (first) Galactic Empire made Trantor its capital planet. It city grew to encompass the world, and developed multiple layers as well. However, the topmost layer is domed over, and ironically creating habitable areas; plant life has even managed to gain a foothold on the surfaces of the artificial structures. Everybody just chooses to live in enclosed sectors. This is inherited behaviour from their ancient ancestors on Earth, as depicted in The Caves of Steel (see above).
• Fragment: The sequel, Pandemonium, is primarily set in and around a massive subterranean Soviet Era city complex constructed during the Cold War underneath the Ural Mountains known as Pobedograd. As the city was being constructed, the slave builders Dug Too Deep and unearthed the titular Pandemonium, a Lost World over 300 million years old filled with Fungus Humongous, Living Gasbags, Big Creepy-Crawlies, and Puppeteer Parasites.
• Goblins in the Castle: The land of Nilbog is mainly one big city, in a deep, dark cavern.
• Heavy Object:
  • Civilians in the Greater Canyon region have expanded former nuclear missile silos into underground bunker cities. The surface populations alone can reach the thousands with the wealthiest individuals living on the deepest levels.
  • Organizations focused on spaceflight eventually concluded that civilization on Earth was going to collapse before a viable colony in space could be established. They instead diverted their funds into building elaborate, self-sustaining bunker cities where the elite could ride out the apocalypse in comfort.
• Hellstrom's Hive: Hidden under a farm in Oregon, the Hive is 5000 feet deep and contains a tunnel system housing around 50,000 inhabitants. Hellstrom claims it can survive the explosion of a hydrogen bomb. A government agency gets an unpleasant surprise when they try to seize the farm by force, thinking there's only a small group of civilians there.
• Honor Harrington: Lower levels of Old Chicago are literally a Buried City, having been basically roofed over by the newer construction in the two millennia that have passed since, with much of what is a current city largely recognizable and still well lived-in. The Loop, although deeply underground now, is a lively bohemian quarter, although with a (not undeserved) somewhat seedy reputation, and Soldier Field is a popular venue for political rallies. Going even deeper, on the other hand, is... not recommended.
• The Hunger Games: District 13 is a former Apocalypse Bunker that acts as a semi-independent city-state. Daily life is extremely regimented; presumably this lifestyle, along with a diet of future food, enables humans to survive underground for long periods.
• Hyperion Cantos: The high-gravity world Lusus, where all settlements are for some reason underground "Hives" carved into the rock. These are quite extensive; Lusus is a major center of economic and political power in the Hegemony and subsequently.
• Imperial Radch: The novel Radiant Star is set in Ooioiaa, a city excavated deep beneath the surface of the icy Rogue Planet Aaa. The local religious communities believe that the first settlers were called to the site by a cosmic force called the Radiant Star, though the narrator admits that historical records are unclear about the practical details of the city's founding.
• Is It Wrong to Try to Pick Up Girls in a Dungeon?: The town of Rivira is located on the 18th floor of the dungeon deep beneath Orario. It used to be Guild-sponsored but the cost of maintaining it was not worth the benefits they were getting, so they abandoned the initiative. Didn't stop Adventurers from running it themselves since it was useful enough for them and they could save on defence costs by abandoning the town in case of attack, an option not really available to the Guild.
• The Last Adventure of Constance Verity:
  • There is a city beneath Chicago ruled by a Vampire Monarch that used to be famous mobster Al Capone.
  • There is a "Sunken City of the Chaos Gods" under Wichita, Kansas.
• The Legend of Drizzt: Drow live in city-states in the underground domain called the Underdark, after being (supposedly) chased there by the elves. The best known of these cities is Menzoberranzan, the birth home of The Hero, Drizzt Do'Urden. It has 20,000 drow inhabitants plus hundreds of thousands of slaves, grows giant mushrooms and Rothe livestock and trades with other underground humanoid races.
• In Limbo 1952 by Bernard Wolfe (set in post-WWIII 1990s), the protagonist is surprised to find himself driving through a vast factory built under the Shining City above. The whole set-up is automated, although discrimination still continues with the black population being used for the cleaning and maintenance crew. During the subsequent war, sabotage — or just destruction from atomic bombs going off — causes the whole city to collapse into a massive trench.
• Mermaids (2001): Morva takes Rani Gene Hunting to a vast underground network of caverns beneath the seafloor that only merfolk with magic powers can enter. Morva thinks Rani's surviving family lives somewhere in the city in the caverns.
• The Mermaid Variations: The cities on the moon seem to consist of individual above-ground houses, but each house contains a stairwell that leads into the communal caverns where the lunar Fish People actually live.
• The Moon Is a Harsh Mistress has the Loonies living primarily in underground warrens, with all cities carved out of the Lunar regolith instead of being built atop it, with a few surface installations for access points. This is primarily because the moon being an airless environment, keeping the livable areas pressurized and comfortable is easier when they are built into the ground.
• Shadowmarch: Funderlings designed and built an entire town beneath the Southmarch castle, as well as labyrinth of caverns and tunnels beneath it. Similar subsurface Funderling town exist beneath Syan, and there are probably other beneath various cities through Eion.
• Tales of the Magic Land: The third book, Seven Underground Kings, introduces the Cave of the Ore-Diggers and its City of the Seven Lords to its alternate Land of Oz setting, spending almost half of the book developing their history and lore before the main characters even swing by.
• Tolkien's Legendarium: Dwarves often lived in such cities.
  • The Hobbit: Before it was conquered by Smaug and turned into his personal treasure horde, Erebor was a dwarven city ruled by the King Under the Mountain.
  • Lord of the Rings: Khazad-dûm, aka "the Mines of Moria," was one of the oldest and grandest dwarven cities in existence until its inhabitants Dug Too Deep and awakened an angry and powerful balrog.
  • The Silmarillion: Two other dwarven cities, Nogrod and Belegost, existed in the Blue Mountains, and dwarves from them carved out the Thousand Caves of Menegroth which served as the capital of the Elven kingdom of Doriath. All three were sunk beneath the sea at the end of the First Age.
• Vorkosigan Saga: Beta Colony was one of the earliest interstellar colonies established, before the Wormhole Nexus was discovered. The planet is inhospitable to human life, so the colony is underground. Space is at a premium, so strict Population Control is employed, although thanks to perfect contraception sexuality is largely unrestricted.
• The War Against the Chtorr. In the short story It Needs Salt, Manhattan still has its skyscrapers but has an extensive underground city beneath as well. Unfortunately now that most of the city has been abandoned after the plagues, the lower levels have become a potential breeding ground for the invading Chtorran ecology.
• Wise Phuul: Kuolinako, the capital city of the Viiminian Empire. Centuries of pollution have something to do with it.
• The Witchlands has the mythical Lovats undercity, an alleged city built underneath the "modern" Lovats by ancient Earthwitches. Eventually, it turns out that the undercity is real, and Lovats gangs are using it as their hideout. It proves to be a good housing for all the refugees pouring into the city. The reason behind its construction is unknown, but given that Lovats' location is a natural fortress, it might've been built to house surrounding population in times of war.
• There's one beneath Faery Airbase in Yukikaze, which is where most of the FAF's forces live. It's got what you'd expect of a normal airbase "town", including shopping malls, convenience stores, public transport, and of course housing. It's implied that similar underground cities were built under the other 5 major FAF airbases.

• The 100: The Mountain Men live in an enormous underground military bunker inside Mount Weather, which survived the atomic war and has been transformed into a self-sufficient society by the survivors inside it.
• The Avengers (1960s): The villain in "The Living Dead" has an army in a city built inside an abandoned mine, to seize control of Britain after the country has been obliterated by a nuclear strike from an unnamed enemy.
• Babylon 5: The Shadows have moved all their cities underground for security. For some reason, though, they still have large dome windows on the surface, just large enough for a medium-sized starship to come crashing through.
• Cleopatra 2525: All of humanity live in underground cities because robo terraformers called Baileys roam the surface killing any human they find up there.
• Defiance: Most of what was once Saint Louis, Missouri, has become a Buried City due to malfunctioning alien terraforming technology being accidentally released, causing massive cataclysm across the planet Earth. The locals fled and it is uninhabited, though almost perfectly preserved. The town of Defiance was built on top of the city as a mining outpost to dig for the resources—and the alien technology—it held.
• Falling Skies: Starting with Season 2, the remnants of human civilization are living beneath the city of Charleston, South Carolina in an Apocalypse Bunker.
• The Lord of the Rings: The Rings of Power: As expected from one of the oldest and grandest dwarven cities, Khazad-dum thrives with life. The city is flourishing and has it's own ecosystem maintained by dwarfs.
• Paradise: The United States Government, in preparation for an Extinction Level Event caused by a massive volcanic eruption, constructs a massive underground city beneath Colorado, named "Paradise". The city is stated to house over 25,000 individuals whom were hand selected to live in the bunker by the government. The city is self-sufficient, and contains everything from government buildings to a library, meeting centers, functioning vehicles and even a fake sun, providing residents with an illusion of the world they once knew.
• Sanctuary: Praxis, a large underground city with advanced technology where humans and Abnormals live.
• Star Trek: The Original Series: In "Spock's Brain", the Eymorg inhabit an underground city built after their planet suffered an ice age. Because all their needs are catered for in the city, over thousands of years their intelligence has atrophied until they have the mental age of children. Their society is also split on gender lines, with the Eymorg being a Lady Land that periodically captures Morg (the tribes of male primitives who live on the frozen surface) for breeding purposes.
• Star Trek: Voyager: The Ocampa lived in an underground city provided by the Caretaker, to atone for his species being responsible for the accident that devastated their civilization, after their advanced technology unwittingly caused the planet's surface to become barely habitable.

• Jeff Wayne's Musical Version of The War of the Worlds has a song voiced by David Essex called "Brave New World", which is about the Essex character (a former army engineer) seeking like-minded people to help him to establish such an underground city.
• Tom Waits' song "Underground" is about this.
  There's a big dark town
  It's a place I've found
  There's a world going on underground

• Malevolent features one hidden under a hotel in the sleepy town of Leerie, which serves as the base for the Cult of the King in Yellow. It appears that no one actually lives there, however, as the only residence our protagonists enter only houses a dead body.

• Journey into Space: In Journey to the Moon / Operation Luna, the Time Travellers built an underground city on Earth thousands of years in the past. It is located under a desert which would later become the Mediterranean Sea. They destroy the city once they abandon Earth and take up residence in another underground city on Venus.

• Achtung! Cthulhu:
  • Object 143 is an underground city in Central Siberia once inhabited by the mi-go and discovered by Leonid Kulik in 1927. Kulik describes Object 143 as an enormous underground settlement comprised of several thousand basalt structures incorporating bizarre, unnatural geometry. Some sections of the city appear to have been laid waste by a powerful weapon, while others remain strangely intact.
  • Access to the naga city of Hsatth is through three miles of twisting and treacherous caves which the naga can navigate effortlessly, but which present considerable dangers to humans.
• Anima: Beyond Fantasy features a huge, sprawling ancient city buried beneath the city of Hecate.
• Dungeons & Dragons: Various settings feature races such as Dwarves, Dark Elves (a.k.a. Drow) and Illithids living in huge underground cities, often including vast open spaces and even farmlands (usually growing some kind of mushroom-based crop).
• Earthdawn. The entire population of the Earth had to hide from an interdimensional invasion. Most of them constructed and found refuge in kaers, magically protected underground cities. The dwarves of Throal actually hollowed out a mountain and used it as their kaer.
• Invisible Sun has the unsavory Undersling, located beneath the City of Satyrine. However, the underground concept is played with in that thanks to the Actuality's Alien Geometries, it is a piece of land hung from hundred of wires, ropes, and chains beneath the structure of the city itself.
• Isaac Asimov's Robots: Rather than presenting a Layered Metropolis and Mega City like in the books, this game simply says that humans have "moved underground". Exterior shots, however, show a Domed Hometown. The sky is only ever shown in Spacertown because the Earthers have been living underground for so long, they're not used to the fresh air or sunshine. They find the idea abhorrent.
• Mutants & Masterminds: The Atlas of Earth-Prime has Ondersdam, beneath Amsterdam. Based around an Atlantean outpost which has apparently been there since before the damming that created the "overground" city, now occupied by Morlock and Sub-Terran refugees.
• Paranoia takes place almost entirely in Alpha Complex, a massive underground Arcology run by an utterly insane computer. Well, possibly, it might be a Domed City, or underwater, or a space station, the truth is unavailable at your security clearance, Citizen!
• Tails of Equestria has Umberfoal.
• Vampire: The Masquerade:
  • The sewer dwelling Nosferatu. If enough of them made their home in a given city's sewers they would eventually begin to burrow and carve out an actual underground home for themselves away from the prying eyes of mortals and vampires. They did this not just to hide their Masquerade breaking Red Right Hand, but to escape the notice of the Nictuku, their cannibalistic "older brothers". In an odd inversion, they didn't dig deep enough.
  • For examples that aren't Nosferatu centered, it's noted that the Sabbat of Montreal take plenty of advantage of the city's Underground City (actually a series of interconnected metro stations, shopping malls, residential centers, and offices), setting up Havens in the disused parts and using the underground sprawl as a convenient place to pick off victims.
• Vampire: The Requiem's Nosferatu are less restricted in where they live, but their clanbook actually details how they can build a literal Necropolis for themselves. For that matter, much of the kindred population in ancient Rome lived in Nosferatu dug warrens.
• Warhammer:
  • Dark Heresy: The people of Vouxis Prime hid underground to escape the war between Orks and another alien race that ravaged their world. They eventually excavated immense underground cities, resulting in a sort of inverted Hive World where the population inhabits immense, kilometers-deep and ornately decorated tunnel-cities and only the poorest eke out a living on the dry and desolate surface.
  • Warhammer Fantasy:
    • The Dwarfs live in enormous, masterfully carved and decorated fortress cities beneath the World's Edge Mountains, as well as in several lesser mountain ranges across the Old World. These generally start out as mining settlements, growing with time into massive, self-sufficient underground redoubts, home to vast numbers of Dwarfs. Sufficiently large Dwarf neighborhoods in human cities tend to develop a similar character; for instance, Metallschlacke, Altdorf's Dwarf quarter, extends several stories downwards into the Niederwind sub-district, where a majority of the city's Dwarfs actually live.
    • The Skaven live in an underground empire, vast with tunnels that connect their countless underground cities across the known world, from the jungles of Lustria, to the Old World, to Nippon. Their capital city, Skavenblight, acts as the very center of their underground tunnel network.

• Geofront in Ace Combat 3: Electrosphere is an underground city large enough to have skyscrapers and highways, in the center of an enormous network of tunnels that serve as the game's usual tunnel mission.
• ANNO: Mutationem: Beneath Freeway 42, there's a regimen of dwellers converted into robots by the Mechanika Virus living far underground. The tribe living there would lose any sense of identity upon the virus damaging their minds and end up being split off into the nearby ruins.
• The eponymous Arx of Arx Fatalis is a bunker city built in collaboration by all the races of the planet on realizing their sun was going dark, plunging the surface into permanent winter. The various races have set up their own settlements at different locations throughout the caverns. There are also other bunker cities scattered across the world which sometimes trade with Arx.
• Asheron's Call had at least two examples. The first was actually called "The Underground City" and it was the former home of Elysa Strathelar and Thorsten Cragstone's rebels. The other was Xarabydun, a settlement in the middle of the desert strangely full of plant life.
• Baldur's Gate II has an underground Monster Town, the so called Ghoul Town, below Athkatla. It is reached through the "Pit of the Faithless" inside the hideout of the Cult of the Eyeless, from where those who fail to join the cult are thrown and their bodies become food for the ghouls. The cultists could be argued to live in their own underground city too (although it is more akin to a single excavated apartment/refuge in the Absurdly Spacious Sewer), which in turn is connected also to a beholder lair which still qualifies from the point of view of beholders.
  • There is an abandoned temple of Amaunator with its last followers dwelling there, which can be reached from a passage in the same area where the cult hideout is.
  • Even further down is the Underdark, where you get wrapped up in an entire plot arc in the drow elven Wretched Hive of Ust Natha, and their neighbours, including a svirfneblin town, a stronghold of mind flayers, and another lair of Beholders.
• Batman: Arkham City: Wonder City was an Edwardian-era city designed to run on clean Lazarus energy, protected by robot guardians instead of a human police force. Unfortunately, Wonder City failed because exposure to Lazarus leads to insanity. The city was abandoned and eventually built over, but Wonder Tower is still visible and became Professor Hugo Strange's command center during his reign as warden of Arkham City. Ra's al Ghul had created Wonder City after he discovered a Lazarus pit in Gotham back in the late 19th century.
• Cave Story: The huge cave system underneath the island houses Mimiga Village, along with shops and homes scattered from Grasstown/Bushlands to the Labyrinth and everywhere in-between. Then it's revealed that both the cave system and the island are floating high above the clouds.
• DROD 3: The City Beneath: As you might guess from the title, the game opens with Beethro discovering one of these — the hub of the Rooted Empire, an entire underground civilisation with tunnels linking to all corners of the aboveground world.
• Non-Karma Society members in Digital Devil Saga 2 live in an underground city, because the blackened sun turns people to stone. Karma Society members live under a glass dome.
• Drakensang: The dwarven city of Murolosh.
• If it survives long enough, a Dwarf Fortress that grows from outpost to Elaborate Underground Base will eventually be a full fledged self-sustaining city able to go without outside trade. That's a big IF though.
• Eastward: Potcrock Isle is a large community of people who live underground and are forbidden from exploring the surface above them as they have been taught that The MIASMA has made it uninhabitable.
• Torin in Echoes is astonished to find an Inhuman Borough in Devil's Arse, inhabited by an assortment of Always Chaotic Evil races who, thanks to Jewel of Harmonia, get along more or less fine. Later his sidekick Belgrub spends more time there, talking to inhabitants (mostly to goblins, but also to orcs) and doing adventure game things.
• The Elder Scrolls:
  • In the series' lore, the vanished Dwemer were fond of building these, crossing over with Advanced Ancient Acropolis. Due to their Ragnarök-Proofing, many are still standing throughout their old territories, particularly in Morrowind, which was the epicenter of their ancient culture.
  • In Oblivion, this role is taken by Ayleid Ruins, underground dwellings of the ancient Wild Elves. In some cases the above-ground portion of an Ayleid site is no more than a doorway, but underground they can be huge, elaborate mazes with as many as five separate sectors. For the largest Ayleid ruins, getting lost inside is a very real danger.
  • Skyrim has Blackreach, an underground Dwemer ruin so massive it has four separate surface entrances, its own Optional Boss, and an entire castle. There are other, smaller Dwemer ruins throughout the game as well.
• Eternal Darkness: The city of Ehn'ga exists beneath the Roivas mansion. It was home to a civilization that Augustus's Ancient patron destroyed eons ago.
• The entire premise of Fallen London is that London has been dragged into a cavern a mile below the surface by Eldritch Abominations. It's the fifth city to have received this treatment, and the cavern is vast enough that the are many other cities down there, most predating London. Dig deeper yet and you'll find Flute Street, which is populated by squid men.
• Fallout: The Vaults enabled humanity to survive nuclear war in America, but just barely. And they were intended as proof-of-concept models for a Generation Ship that wasn't built in time, hence the various experimental (and often sadistic) situations manufactured. Some weren't even finished, like Boston's Vaults 88 and 114. Fallout 4's "Vault-Tec Workshop" allows The Sole Survivor to build Vault 88 into a functioning settlement, as well as ignore the Overseer's pointlessly cruel experiments.
  • The original Fallout 1 had the Slag AKA Pale Folk underground community, with the inhabitants a group whose ancestors mutated to have pale skin, very sensitive eyes, etc.
  • Fallout 4 has the Institute, a shining, futuristic scientific utopia located beneath the old Commonwealth Institute of Technology. It's also a slave society that has no qualms about kidnapping wastelanders, conducting horribly unethical experiments For Science!, and terrorizing the Commonwealth with their synth spies.
• Final Fantasy:
  • Final Fantasy IV: Both the Dwarven Castle and Tomra qualify, by virtue of being located on the underworld deep inside the planet.
  • Final Fantasy XII: The Lowtown of Rabanastre. It was formerly a warehouse, but was converted into residences by the people of Rabanastre who were driven to poverty as a result of the Archadian invasion.
  • Final Fantasy XIV: The Kobolds are a race of mole-like people residing in La Noscea, particularly on the northern side of the region within O'Ghomoro, their mountain and volcanic home.
• Fire Emblem:
  • In Fire Emblem Fates, a big example in Nohr is almost the entire population living either in these or in walled towns, if not in places that mix both, because of the incredibly brutal reign of their king and the harsh living conditions. This includes the Nohrian capital, Windmire◊.
  • Fire Emblem: Three Houses gives us Shambhala, the home base of those who slither in the dark, which also happens to be an Elaborate Underground Base complete with lasers and Humongous Mechas, with a distinctly Magitek feel to distinguish themselves from any other villains previously encountered in the series. It is rather clearly established that this is where the remnants of the Agarthans escaped and hid since their rebellion against the goddess thousands of years before the game begins. Also there is Abyss, a major setting of the "Cindered Shadows" side story. Located deep under the Garreg Mach Monastery, Abyss is home to the huddled masses of Fodlan and are treated as the church's barely-tolerated secret.
• Guardian Tales: What remains of the ancient city of Demonshire is the underground city of vampires. Demons from the surface section of the city fled beneath the earth in hopes of co-existing with the vampires after the Demon World Reunification War completely annihilated the surface city and rendered it inhospitable for more than 13,000 years, where they together created the Artificial Sun to support the life of the refuges without harming the natives.
• Hollow Knight: Most settlements in the game are underground, but the one that qualifies the most is the old capital city of Hallownest, known today as the City of Tears. It features tall buildings, some of which reach from floor to ceiling, perpetual rain due to infiltration from the Blue Lake above, and judging from the spikes on most roofs, must have had a flying pest problem just like human cities do.
• In Legend of Legaia, the caverns under Octam are this. Originally the ruins of a lost civilization, it was cleared out so that the inhabitants of the town above could build new houses and escape from the Mist. The people of Octam have been living down there for 10+ years by the time Vahn and his companions arrive, slowly being killed by earthquakes that have been destroying their homes.
• In Master of Orion II, the Sakkra are a reptilian civilization with a penchant for underground cities, effectively doubling the population that can inhabit a planet and making orbital bombardment harder, as well as give defending ground troops a +10 advantage over any invaders other than the Bulrathi, who get the same amount of boost due to their strength.
• Might and Magic and Heroes of Might and Magic:
  • The Dwarves in Might and Magic VII have the underground Stone City as their capital city. Somewhat downplayed in that they also have surface villages and barrows only accessible from above-ground and other barrows (the Nighonians apparently also have great underground cities, as per what is said and what we see in Heroes of Might and Magic III, but the settlements of theirs we actually get to visit are above-ground). The Deyjans also have their capital city, the Pit, underground (unknown how deep, since unlike Stone City getting to the Pit includes going through a teleporter).
  • Balthazar's Lair, capital city of the Minotaurs, is this in Might and Magic VIII. It's also flooded and infested with Tritons at the beginning of the game, with one of the mainline quests requiring you to drain the place and kill the invaders. Once you accomplish that, it has everything a standard city has, from tavern to armory store, and even a couple of trainers.
  • Also in Might and Magic VIII, the Elemental Plane of Earth is a complex maze of tunnels and caverns, including houses for its iinhabitants and the palace guarding the Heart of Earth.
  • In Ubisoft's new continuity (Heroes V and onward) the Dark Elves Dungeon faction have their cities underground.
• Myst gradually reveals that the lost city of D'ni is in a five-mile-wide cavern three miles below the surface of the Earth, with a lake of glowing algae that acts as a light source, somewhere beneath a vast stretch of desert in New Mexico ^note There's some early ambiguity about it being there or in Egypt, with Cyan Worlds "claiming" that since the Myst saga is based on a true story and a real archeological find conscience dictates that they keep the location a secret, but a sign near the property entrance in Uru identifies the specific county, and promotions for the game gave the exact coordinates where the Cleft is supposed to be. Uru: Ages Beyond Myst permits a virtual exploration of D'ni itself.
• Paper Mario:
  • Paper Mario: The Thousand-Year Door: Directly underneath Rogueport is a town built into caverns that Rogueport's Absurdly Spacious Sewer passes through. Most of the inhabitants of this unnamed town are in hiding from someone on the surface and have fled here because few people in Rogueport know about it. The buildings themselves, however, have existed for at least a thousand years, with the current inhabitants having appropriated the ruins as their living quarters—the civilization that used to live in them was wiped out by the Shadow Queen and left abandoned for centuries, until settlers arrived and built on top of the ruins what would become the current Rogueport.
  • Paper Mario: The Origami King: The southwestern end of Breezy Tunnel is a town inhabited by Monty Moles. It consists of an artificial cavern with wooden paths built into the walls and wooden bridges laid around where necessary. The Monty Moles continue to dig into the walls to expand the town.
• In PlanetSide 1, the Caverns introduced in the Expansion Pack appear to be these. Vast chambers are filled with floating ancient Vanu constructs and buildings, with high-tech ziplines crossing the complex three-dimensional environments. Some caverns are underground, some are inside asteroids spinning through space, and some have no apparent exit aside from the geowarp Portal Network.
• Pokémon:
  • An attempt at this was made in Pokémon Ruby and Sapphire with New Mauville, an abandoned underground power plant on the outskirts of Mauville City that was originally intended to be a 69-floor subterranean city. The project was scrapped for environmental reasons after Electric Pokémon started using it as a nesting ground, and in the present day Gym Leader Wattson sends Brendan/May on a sidequest to shut down its defective generator.
  • Pokémon Colosseum has the Under, a town in the old mines beneath Pyrite Town. Originally built to save the miners the commute to and from the surface, it is now populated by their descendants and at the start of the game is ruled openly by the crime syndicate Cipher. The player frees the town, and by the time of Pokémon XD: Gale of Darkness everyone has moved to the surface and the town itself has been buried.
• Professor Layton and the Unwound Future has one under the city of London. The inhabitants are made to believe that it is located in the future.
• In the backstory to RayForce, humanity attempts to take refuge from the evil Master Computer Con-Human's forces by developing cities underground. It doesn't work, and they're forced to flee into space.
• In RimWorld, it's entirely possible, if time-consuming, to dig into a mountainside to build an underground colony. Such a base will be easy to defend, immune to Drop Pods or mortar fire, and will enjoy a year-round moderate temperature while ignoring heat waves or even disasters like toxic fallout (especially if you build some hydroponic gardens). But they also present their own challenges: Cabin Fever will impose increasing mood penalties on colonists who miss the sun, careless digging can cause deadly cave-ins, and at any moment a swarm of Big Creepy-Crawlies might come burrowing up out of the floor to build a new hive.
• Rogue Legacy 2: What Genesis actually is. Cain arranged for the place to be constructed and manned expressly to make harvesting the Tree of Life's next fruit that much easier, especially since he'd be free to take over ever more of the surface world in the meantime.
• RuneScape has several underground cities. The Dwarvern city of Keldagrim and the cave goblin city of Dorgesh-Kaan are the inhuman type occupied primarily by their respective species. The city of Senntisten was the former capital of the Zarosian Empire until it was buried during the god wars.
• Shin Megami Tensei IV has the "country" of the "Unclean Ones" deep in the depths of Naraku, a demon-infested cavern underneath Mikado. That "country" is actually Tokyo, Japan, which was rendered underground by a layer of bedrock 25 years ago—or about 1500 years ago from the perspective of Mikado—to protect the city from a catastrophic nuclear strike.
• Skies of Arcadia: The city of Glacia was carved under thick ice sheets by the purple moon civilisation. This fact spared it from the Rains of Destruction that devastated the other old world civilisations, making it the last intact remnant of that era. However, the city is completely abandoned by the civilisation that built it, and where they went and why is a mystery for the ages.
• In the Splatoon series, most Octarians live underground in domes designed to emulate the above world. Unfortunately, they're running out of resources; they used to live above ground but were forced underground after a war with the Inklings a century prior to the events of the first game. The first artbook establishes that said domes are actually ancient human shelters designed to shield their occupants from rising sea levels and global conflict, with Splatoon 3's Hero Mode taking place inside one that humanity actually managed to find refuge in, at least until they ended up wiping themselves out anyways.
• In Stellaris, one of the many Origins introduced in the Overlord DLC is Subterranean, an Origin that uncaps the amount of Mining districts you can build to the effective district cap of your planet, a special Cave Dweller trait for your species, two extra housing per Mining district (instead of the two you normally get), a building slot every three Mining districts built, and a -75% damage reduction from orbital bombardment. Combined with the right number of species traits, traditions, civics, and technologies, a Subterranean empire is a literal empire of fortresses capable of stalemating anything thrown at it. Downsides include higher upkeep and a slight increase in build times, but otherwise negligible.
• Stray (2022): The entirety of the game takes place in a massive underground city known as Walled City 99 (a reference to the Kowloon Walled City, which the game's setting is heavily inspired by). The city has been stuck in lockdown mode for centuries because the controllers died of a plague which wiped out humankind. At the end, B-12 and the cat are finally able to open the roof and let real sunlight down into the city.
• In Temtem, the island of Tucma is a Death World with most humans living in the elaborate underground city of Quetzal to avoid the poisoned surface. Over time Quetzal developed into a mining and manufacturing town (loosely based on the mining communities of Andean Argentina) that exports metalwork and jewelry to the other islands.
• Former Hell, introduced in Touhou Chireiden ~ Subterranean Animism. When Hell moved from underground to somewhere else, Yōkai who were hated because of their powers decided to move to the old location. They formed a contract with the above-ground youkai, where the above-ground youkai are forbidden to go underground, while the underground youkai keep the remaining evil spirits sealed.
• Undertale has the monsters living underground below a mountain after losing the war against humans and being banished to the underground after the humans sealed them there. Despite living underground, the monsters have water, food, towns, internet, and a working laboratory. However, it is implied that life underground isn't all that great and the monsters wish to live on the surface again and it can actually happen in the Golden Ending where they see the sky for the first time.
• Parts of Leá Monde were buried in the earthquake that caused its abandonment in Vagrant Story.
• World of Warcraft: The capital city of the Forsaken undead is the (aptly named) Undercity. It was originally just a series of sewers and catacombs below the palace of Lordaeron which Arthas ordered enlarged to act as his base of operations. When he departed for Northrend, the Forsaken and Sylvanas Windrunner claimed it for themselves.
  • This is a running theme for the dwarves who have several underground cities, though only one is fully under their control.
    • Ironforge is the home city of the Bronzebeard dwarves and capital city of the united dwarf nation. It's built inside of a mountain ridge and is easily the most well-defended of the original Alliance cities.
    • Blackrock Mountain was originally the home of the entire Black Iron dwarf nation, its walls honeycombed with their dwellings and monuments. When the Black Dragonflight and Old Horde invaded, the mountain became split between their two cities: Blackrock Spire, the old city inhabited by the Old Horde; and Blackrock Depths, a new city carved out beneath the Spire to house the displaced dwarves.
    • Grim Batol was originally the fortress city of the Wildhammer dwarves until it was abandoned due to an "evil taint". Its layout is very similar to Ironforge and there are signs that it extends much further underground than can be visited in-game.
  • The goblin capital of Undermine is built in a series of volcanic caverns and magma tubes beneath their home island. The current state of Undermine after the volcano's eruption is unknown.
  • Ahn'Kahet is an underground city that here and there borders natural subterranean life. It features large, glowy mushrooms, insects of different types and sizes and bioluminiscent birds/bats that fly around. It also contains large number of undead that took over the city as well as the few surviving Nerubians that orginally inhabited the city. While the dungeon itself is fairly linear, players are able get a good view of the massive underground caverns from ledges and combinations of creepy music, darkness and mysterious whispers (courtesy of an Old God under whose range of influence the city is located) make this place quite Nightmare Fuellerific.
  • The former gnome capital of Gnomeregan was such a city until a series of disasters left it an irradiated warzone. As such, the city is now a mid-level dungeon and the gnomes who escaped have set up "New Tinkertown" (after the gnome district in Ironforge) outside the gates of Gnomeregan as their new capital.
• Beneath the world of Wuppo lies Popocity, a sprawling underground metropolitan area build by the Wums in search of a new and interesting place to live. It's connected to the surface by the Popotrain, a vertical transport operated by chain links and rails.
• All of Wynncraft's dwarven cities count as this. Thanos is located underneath a spire in the Canyon of the Lost while Maex and Rodoroc are found in the Molten Heights' lower layer, which is basically the region's cave system.

• Charby the Vampirate: The Orycalope Kingdom was dug into the hills as a series of labyrinths and underground cities. They kept to themselves which meant many of their nearby neighbors were not even aware when the orycalopes were massacred by King Rodericke. Those living nearby did notice that there were suddenly a lot more vampires around as the newly emptied underground cities proved a convenient place to stay out of the sun during daylight hours.
• Drowtales: Similarly to Forgotten Realms (on which the comic was originally based), drow live in underground cities of the "Apocalypse Bunker" subtype after a war that wrecked the planet's surface. Most notable of these is Chel'el'Sussoloth, the capital of the drow nation. The city is split across several caverns that are connected by tunnels and bridges, and the crystal ceiling above it resembles a starry night sky because of reflected light.
• Endtown: The titular city is the Apocalypse Bunker version crossed over with Inhuman Borough because most of the inhabitants are mutated humans.
• Girl Genius: There are apparently multiple underground cities beneath Paris, all incredibly secret and occupied by lost civilisations, apart from the fact that everyone seems to know about them. The two main ones are the Moligarchy, inhabited by a race of Mole Men called the Talpini, and the Silverlands, inhabited by a race of tall, possibly albino humans called the Argurons. They are bitter enemies who have been at war for generations, despite the fact that their throne rooms are within walking distance.
• Nixvir: In the lore, the scarecrows, the rivals of the snowmen, reside in an underground city known as the Sacristy, where they reside in secret, hiding their sentience from the rest of the world. The city is located on a small island in an underground lake, and the gates to the cavern are closed to all outsiders.
  • In the comic itself, we have the city of the kangaroos, which resembles less a bustling metropolis and more of an English village or market town. It was based on the settlements in the Cheddar Gorge in England combined with the Victorian section of Cadbury World). We only get a brief glimpse of this underground city as Erik and Oriel are leaving it.◊
  • The Kingdom of Mannequins is also deep underground in a cavern deep beneath the Boldar Mountains. In contrast to the city of the kangaroos, we don't really get to see it though, because the mannequins have a nasty habit of killing anybody unfortunate enough to discover the place, and so in the desperation to escape, Erik and Oriel don't look around the place.
• Runaway to the Stars:
  • The cities of bug ferrets are not entirely unlike the burrows of colonial rodents in form, just with very high technology and tens of millions of occupants. They are immense, tangled networks of private and public spaces, which aren't often strongly delineated, and connected by mazes of tunnels and ramps. Ferrets, being a naturally subterranean species, can navigate by touch alone at need and don't experience claustrophobia, meaning that these cities can get extremely cramped and dimly-lit from other species' perspectives.
  • It's been mentioned offhandedly that one of the more common types of terrestrial space colonies are vast tunnel systems beneath a planet's surface, because it's a lot cheaper and faster to build than terraforming the entire planet or constructing enormous dome cities.
• Sam & Fuzzy: The Underground is made up of several of these, with several US towns and cities having sub-cities built directly underneath or nearby underneath. Amongst the major ones are Retropolis (located underneath rural Pennsylvania), Sub-Newport (underneath Newport, Oregon) and Megalopolis (underneath Los Angeles, California).
• Woo Hoo!: The Subterrain is a sprawling, steampunk-ish place ruled by a Rat King on a giant toilet.

• C0DA, written by former The Elder Scrolls series writer/designer Michael Kirkbride, takes place in the far distant future of TES universe. Numidium, the Reality Warping Humongous Mecha of Dwemer construction, presumed destroyed following the events of The Elder Scrolls II: Daggerfall, returns after having been caught in a time warp. It continues its war on the Aldmeri Dominion, led by the fascistic Thalmor, leading to an apocalyptic event known as "Landfall", which has forced the remaining inhabitants of Nirn to take refuge on the moon Masser. There, they have built the city of Ald Sotha in a series of connected caverns under the surface. It serves as the setting for most of the story.
• Critical Role: There's the duergar city and the illithid colony of Yug'Voril deep in the Underdark.
• Mahu: In "Second Chance" the fleeing people of Earth appear on a new planet covered in ice and snow. The surface makes like difficult, if not impossible, for normal humans, so most of them choose to inhabit and create expanding cities underground.
• Paranormal High School: Hikaru, Kuroi and Riku end up finding one in Osaka during the Summer 2025 arc, chasing after Yellow Riko. It's revealed the city itself was in part constructed by her thanks to her unique ability of Fast Tunnelling, with other landmine girls deciding to move in after finding it.
• RWBY had the settlement of Mountain Glenn. Originally an above-ground city outside the walls of Vale, when it began to be overwhelmed by Grimm, the city moved into the large caverns below as a last-ditch effort to survive. It worked for a while, but eventually the Grimm got there too.
• SCP Foundation:
  • SCP-110 is a city underneath a farm in New York that was displaced across time, although it was apparently already underground when it was built.
  • SCP-1678 is a replica of Victorian London placed underneath the real London, and intended to serve as an Apocalypse Bunker.
  • The purpose of SCP-752 is to create a perfect utopia underground possessing higher levels of intellect along with the technology they possess. However, their overall goal has cost them their own basic human moralities, and they have developed a behavioral system which contains no self-interest in likeness to ants and fundamentally works for the 'greater good' of society. That being said, containment protocols states that it is best for them to not know the surface above them, as they're no longer considered human and can lead to a total dominance shift in species.
  • Eurtec is an underground European city run by the Global Occult Coalition's less trigger-happy side, which is nonetheless a place of incredible inequality and often a den of crime.
• Taerel Setting: Examples of this include the the Muvon City Zu'aan's city and the Keduk City Zu'aan's city, both being underground cities.
• Welcome to Night Vale: Night Vale's Desert Flower Bowling Alley and Arcade Fun Complex is purported to contain a vast underground city beneath the pin-retrieval area of lane five. Expectations are confounded when it turns out the city beneath Night Vale is actually a miniature metropolis.

• In Amphibia, The Olms keep to themselves in their underground city of Proteus, and consider the surface to be "outsider business".
• Ben 10: Omniverse eventually developed Undertown, an entire city hiding underneath Bellwood's sewers where a great many species of aliens and traders make their living here outside of the watch of humans.
• In Futurama, the ruins of old New York are mostly intact directly beneath the active New New York. The subterranean section is inhabited by mutants and considered no-go for regular citizens.
• Kipo and the Age of Wonderbeasts: Of the "Apocalypse Bunker" type. Kipo's original home was a town built into a large hollow space underneath a cloverleaf highway interchange, with another bunker being located underneath a field of Mega-Dogs.
• In Mixels Nixel Land is contained under Planet Mixel, and uses natural craters and potholes to go into Mixel Land.
• Almost all of the settings seen in ''Slugterra, understandably given that the show takes place in an underground civilization.
• Sonic the Hedgehog (SatAM): In the Season 1 episode, "Warp Sonic", the Freedom Fighters discover an underground city below Robotropolis, where Mobians are hiding from Robotnik.
• Trollhunters: Heartstone Trollmarket is an Underground City beneath the human town of Arcadia, that acts as a sanctuary and headquarters of good Trolls and the Trollhunters, the various buildings interlaced with giant, phosphorescent crystals.
• Young Justice (2010): In this series, Martian civilization exists entirely underground with many large elaborate underground cities such as the capital Ma'aleca'andra. These cities are connected via numerous underground caverns and even an underground river that is home to various Martian flora and fauna. Said river is also commonly used as part of the traditional Martian marriage ceremony.

• Older Than Dirt: Derinkuyu underground city in Cappadocia region of Turkey dates back to the Bronze Age. Entered through a very claustrophobic cobweb of stairways (large enough for only one fit person, crouching), it was large enough to host a whopping 20,000 people, with refectories, stables, churches and schools included. Cappadocian Greeks used to take refuge in those caves to protect themselves from Muslim raiders, because, well, no enemy army could possibly be crazy enough to even try to enter there.
• In the Moscow district of Ramenki, the enormous and largely empty field behind the main campus of the Moscow State University, has long rumored to cover a sizable underground complex intended as a retreat for key state personnel in case of a nuclear attack. Reportedly it can house 12 to 15 thousand people for at least half a year while completely "buttoned up", is capable of withstanding a nuclear strike and includes an auxiliary command center. It is reportedly connected by the secret subway to various key government and civilian locations including the Kremlin, Moscow State University next door, Vnukovo airport and even Lenin State Library.
• No one knows what they are building at the Mt. Yamantau in the Southern Urals, but it is HUGE — they've been at it for thirty years now, and apparently still haven't completely finished. A whole sizable city of 25000 has been built to just serve the construction effort. The installation is estimated to have been consumed tens of billions of dollars in all those years, and comprise millions of square meters of deep underground space, but what it is used for is drowned under the tons of smoke and mirrors. Sometimes it's the State Reserve warehouses, sometimes it is simply resource extraction, some times it is (sheepishly admitted) nuclear processing plant, but in the end it is still a secret well kept.
• Back when it was still fashionable to use nuclear explosions for the civil engineering, the Soviet Union conducted several of them in Kazakhstan, ostensibly to improve the productivity of the local oil fields (a kind of the fracking writ large, so to speak). The rumor mill, however, has always insisted that at least one of the explosions, that reportedly produced a cavity about a mile in diameter several miles underground, was conducted to construct an enormous bunker in case of a nuclear war. Given the fact that the cavity would have remained radioactive for decades, this seems a little counterproductive.
• Because of worsening relations following the Sino-Soviet Split, Beijing had a large series of tunnels and rooms dug between 1969 and 1979 that the government claimed could all of the city's 6 million people for four months in case of nuclear attack. When it was finished, the tunnels totaled about 85 square kilometers (33 square miles) underneath its streets and would have had space for restaurants, grocery stores, and even movie theaters. When Deng Xiaoping came to power in the 1980's, he ordered the tunnels be opened up for renting out commercial space since by that point relations between China and the USSR had stopped worsening. Though many parts of the tunnels are now officially closed for renovation, it is estimated that today up to 1 million people, mainly poor migrants from other Chinese provinces, currently live in the tunnels illegally due to it being a cheap place to live (around 500 yuan or US$57 per month).
• The South Australian town of Coober Pedy has its buildings, known by the residents as "dugouts" go underground, both due to the town's thriving opal-mining industry and to avoid the heat reaching around 39°C (102°F).
• Building cities underground has been proposed as a more effective (with current technology) means of populating Mars than the Domed City of science fiction.