Proton looked up and saw the rocky cone of Mount Terror, the solar reflector leaning over the armorcrete rim, and the curved magnalloy blades of a blast iris retracted into the sides. The purpose of this construction was suddenly clear. They were inside a depthscraper — a legacy of the time when entire cites were built underground in fear of another atomic war.
— Plan 7 of 9 from Outer Space
A full-fledged city
that lies Beneath the Earth
. It's a civilian form of Elaborate Underground Base
and comparable to an Underwater City
. The underground city is more than a collection of refugees hiding in abandoned sewer and subway tunnels, it has markets, mines, homes and possibly even farms (either of mushrooms and stranger fare or sophisticated hydroponics).
Typically these cities come in a few flavors:
- Apocalypse Bunker: A refuge from an apocalyptic threat, thus serving as a Bottle City capable of weathering everything short of planetary crust destruction via Apocalypse How scenario.
- Inhuman Borough: Home to a non-human or once-human race of Mole Men or home to evolved sentient dinosaurs using it as the above mentioned Apocalypse Bunker. While most of the time the residents are natives of Earth, aliens occasionally live in these.
- Buried City: This was once a thriving surface city that has come to ruin, but also been hidden and preserved to an amazing level underground. Usually thanks to an earthquake. If it was highly advanced it may have survivors in the form of a Living Relic, King in the Mountain, Human Popsicle or Perpetual-Motion Monster.
It is possible that these varieties be combined. For example: a Buried City may still be inhabited and serve as an Apocalypse Bunker, or an Inhuman Borough built by aliens as an Apocalypse Bunker.
The underground city is very often a Hidden Elf Village
and is only rarely part of a larger network of interconnected cities. Usually each is a one of a kind
sovereign and isolated city state. In contrast, one way in which Our Dwarves Are All the Same
is that they tend to live in a network of underground cities.
In videogames, these can be an Underground Level
Anime and Manga
- With Earth's surface being uninhabitable due to constant bombardment and the resulting radation, humans are forced to live in these at the start of Space Battleship Yamato / Star Blazers (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).
- In another Leiji Matsumoto anime, Queen Millennia, the aliens infiltrating Earth set up underground cities to survive the coming apocalypse.
- The city of Lux in Texhnolyze is somewhere in between type 1 and 2.
- At the start of Tengen Toppa Gurren Lagann, 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.
- Yoshiwara in Gintama 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.
- There's an Underground City beneath Fairy Airbase in Sentou Yousei 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.
- United Earth Headquarters in Aldnoah.Zero 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.
- The Marvel Universe has several subterranean civilizations, including The Mole Men, The Lava Men, The Deviants and even a sunken Atlantean city whose inhabitants age instantly when exposed to the surface's atmosphere for some reason.
- In Action Comics #412◊ Superman discovers the existence of an entire underground city beneath Metropolis.
- Xenoarchaeologists in World of Fire 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...
- In the world of The Savage Dragon, Chicago apparently was built over the ruins of an older city, now buried and inhabited only by superfreaks.
- In the Matrix movies the only human city in existence, Zion, is hidden underground.
- The Worker's City in Metropolis 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.
- Atlantis in Atlantis The Lost Empire. Instead of simply being underwater, it was buried beneath the ocean floor, and still inhabited.
- Demolition Man. The part of the Los Angeles population that doesn't accept Doctor Cocteau's rule lives in an underground city below the city's streets. They survive by eating stolen food and rats.
- In 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 City of Ember is set in an apocalypse bunker type of city where their supplies and power source are failing.
- The dwarves of Discworld 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 disgruntled 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.
- In 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.
- The Hyperion Cantos have 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 (the detective and central character Brawne Lamia's father was a powerful Hegemony Senator).
- The Legend of Drizzt: Drows 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.
- J. R. R. Tolkien's 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-dűm, 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.
- In the 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 fairies in Artemis Fowl live in a large underground complex of cities and tunnels as their way of hiding from the "Mud Men" on the surface.
- Gracehope in First Light was built into a glacier.
- Isaac Asimov's Foundation and Robot novels (especially The Caves of Steel) invoke this trope. The capital of the Galactic Empire, Trantor, consists entirely of domed or underground habitats. Ironically, the surface of the planet is perfectly habitable, and plant life has even managed to gain a foothold on the surfaces of the artificial structures. Everybody just chooses to live in enclosed sectors. They may have inherited this from their ancient ancestors on Earth, who due to resource shortages and overpopulation had consolidated into enclosed cities that were far less open and spacious than those of Trantor. Earth humans circa 5,000 A.D. were almost universally agoraphobic, because they lived in an environment of corridors and tunnels (the eponymous "Caves of Steel). The Earth's surface was given over mostly to agriculture.
- Robert A. Heinlein's The Moon Is a Harsh Mistress has the Lunies 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.
- In Cleopatra 2525 all of humanity live in underground cities because robo terraformers called Baileys roam the surface killing any human they find up there.
- In 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 it - and the alien technology - held.
- In Falling Skies, starting with Season 2, the remnants of human civilization are living beneath the city of Charleston, North Carolina in an Apocalypse Bunker.
- The Ocampa in Star Trek: Voyager 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.
- Sanctuary has Praxis, a large underground city with advanced technology where humans and Abnormals live.
- The Shadows on Babylon 5 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.
- In various Dungeons & Dragons settings, races such as Dwarves, Dark Elves (a.k.a. Drow) and Illithids tend to live 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.
- Paranoia takes place almost entirely in Alpha Complex, a massive underground Arcology run by an utterly insane computer.
- Vampire: The Masquerade had 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.
- 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.
- The Skaven in Warhammer Fantasy, their underground empire is vasts with tunnels that connect across the known world. From the jungles of Lustria, the Old World, to Nippon.
- Asherons 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.
- 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.
- Drakensang: The dwarven city of Murolosh.
- 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.
- 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.
- Pokémon Colosseum has the Under, a town in the old mines beneath Pyrite Town that at the start of the game is ruled openly by CIPHER. The player frees the town, and by the time of XD: Gale of Darkness everyone has moved to the surface.
- 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.
- Former Hell, introduced in Subterranean Animism, the 11th Touhou game. When Hell moved from underground to somewhere else, youkai 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.
- 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.
- 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).
- In Ubisoft's new continuity (Heroes V and onward) the Dark Elves Dungeon faction have their cities underground.
- The entire premise of Fallen London.
- 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.
- The Elder Scrolls V: Skyrim has Blackreach, an underground Dwemer ruin so massive it has four separate surface entrances, its own Bonus Boss, and an entire castle.
- 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.
- 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.
- 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.
- 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.
- The eponymous Endtown is the Apocalypse Bunker version crossed over with Inhuman Borough because most of the inhabitants are mutated humans.
- 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.
- The SCP Foundation has some examples, such as SCP-110, a city underneath a farm in New York that was displaced across time (although apparently it was already underground when it was built), and SCP-1678, a replica of Victorian London placed underneath the real London, and intended to serve as an Apocalypse Bunker.
- 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 the Season 1 Sonic Sat AM episode, "Warp Sonic", the Freedom Fighters discover an underground city below Robotropolis, where Mobians are hiding from Robotnik.
- This is very much Truth in Television.
- Before you buy/build your own Moria though, living underground has drawbacks in the form of vitamin D deficiency and depression. Hope your people have access to vitamin D supplements and/or high vitamin D foods such as egg yolk, cheese, juice, cereal, fortified milk and fatty fish.
- Lest you go "but what purpose does that serve?": you need it to absorb calcium. Go without vitamin D? Your bones will become brittle and weak.