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 cities were built underground in fear of another atomic war.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:
— Plan 7 of 9 from Outer Space
- Apocalypse Bunker: A refuge from an apocalyptic threat, thus serving as a City in a Bottle capable of weathering everything short of planetary crust destruction via Apocalypse How scenario.
- Inhuman Borough: Rather than an impromptu bunker built for convenience's sake by surface-dwelling humans, some non-human or once-human subterranean species might live in underground cities out of preference. Down here you might find Mole Men, Rat Men, Dwarves, Goblins, Morlocks or even evolved dinosaur people.
- 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.
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Anime and Manga
- 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.
- 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.
- In 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.
- In another Leiji Matsumoto anime, Queen Millennia, the aliens infiltrating Earth set up underground cities to survive the coming apocalypse.
- 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.
- 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 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.
- 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.
- The city of Lux in Texhnolyze is somewhere in between type 1 and 2.
- 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".
- 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.
- The troll caverns in ElfQuest probably qualify. They're certainly big enough. Blue Mountain probably counts as well if you count the mountainside as ground, even though it's obviously above the surrounding ground.
- In Seven Soldiers of Victory, 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.
Films — Animated
Films — Live-Action
- A Boy and His Dog features fundamentalists living underground in simulated Americana
- 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 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.
- Invoked in Doctor Strangelove by the title 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 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.
- The city of Recoletta in Carrie Patel's The Buried Life, hinted to have grown from an Apocolypse 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.
- An early example is Jules Verne's novel Les Indes noires, which appeared in English under the titles "The Child of the Cavern, or Strange Doings Underground", "Black Diamonds'' and "The Underground City".
- 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 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 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 freaking Manhattan Project, even the powerful protagonist tries not to go down there unless he strictly has to.
- Gracehope in First Light was built into a glacier.
- Isaac Asimov:
- Foundation series: 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, as depicted in...
- The Robot novels (especially The Caves of Steel): Due to resource shortages and overpopulation, Earth's population 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.
- Lower levels of Old Chicago in Honorverse 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, though deeply underground now, is a lively bohemian quarter, though 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.
- 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: 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.
- 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-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.
- Robert A. Heinlein's 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.
- 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.
- 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.
- On The 100, Mount Weather is an underground military bunker that survived the atomic war and has been transformed into a self-sufficient society by the survivors inside it.
- 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 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, South Carolina in an Apocalypse Bunker.
- Sanctuary has Praxis, a large underground city with advanced technology where humans and Abnormals live.
- 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.
- 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).
- Anima: Beyond Fantasy features a huge, sprawling ancient city buried beneath the city of Hecate.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- The Elder Scrolls
- In the series' lore, the vanished Dwemer were fond of building these, crossing over with Advanced Ancient Acropolis. Due to their Ragnarok-Proofing, many are still standing throughout their old territories, particularly in Morrowind, which was the epicenter of their ancient culture.
- 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.
- The entire premise of Fallen London.
- 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 Fire Emblem Fates, a big example in Nohr is almost the entire population living like this, both because of the incredibly brutal reign of their king and the harsh living conditions. Many of the cities and villages are more or less underground and/or walled, if not a mix of both, including its capital Windmire◊.
- 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).
- In Ubisoft's new continuity (Heroes V and onward) the Dark Elves Dungeon faction have their cities underground.
- The D'ni, unwitting instigators of the main conflicts in the Myst series, built a city in a very deep cavern as part of their societal Defector from Decadence initiative. A large part of it can be explored in Uru: Ages Beyond Myst.
- In 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.
- 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 Pokémon 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.
- 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.
- In Splatoon, 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.
- 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.
- 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.
- This is a running theme for the dwarves who have several underground cities, though only one is fully under their control.
- 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.
- 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.
- 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 eponymous Endtown is the Apocalypse Bunker version crossed over with Inhuman Borough because most of the inhabitants are mutated humans.
- In 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.
- The Subterrain in WooHoo is a sprawling, steampunk-ish place ruled by a Rat King on a giant toilet.
- 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.
- 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 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.
- In Mixels Nixel Land is contained under Planet Mixel, and uses natural craters and potholes to go into Mixel Land.
- In the Season 1 Sonic SatAM episode, "Warp Sonic", the Freedom Fighters discover an underground city below Robotropolis, where Mobians are hiding from Robotnik.
- Heartstone Trollmarket from Trollhunters is an Underground City beneath Arcadia that acts as a sanctuary and headquarters of good Trolls and the Trollhunters, the various buildings interlaced with giant, phosphorescent crystals.
- 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, or your design includes skylights or fiber optic connections to let at least a bit of sunlight through. 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.
- As the Cheyenne mountain complex could be called a town at best, the Russians have undoubtedly felt that they could do better:
- 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 counterprodictive.