History Main / ElaborateUndergroundBase

*** Hobbits, despite their general preference for underground living, ''don't'' have these.

* ''Film/TheIsland'': An underground base is used to [[spoiler:house clones who are led to believe that the outside is a wasteland]].

* In a series full of {{Supervillain Lair}}s to begin with, in the ''WesternAnimation/Birdman1967'' episode ("Number One") that brought them into the open and really defined them as a threat, [[NebulousEvilOrganisation F.E.A.R.]] turned out to have one of these. One also appeared in the episode "The Quake Threat" (belonging to Dr. Kiroff).

* ''WesternAnimation/{{Dangermouse}}'' lived in an underground base in a postbox on Baker Street in London, the same road as Sherlock Holmes.

* Don't forget about the Labyrinth in ''WesternAnimation/{{Gargoyles}}''.

* ''WesternAnimation/JonnyQuest'' TOS.

** "The Fraudulent Volcano". A large base was built under/in the title volcano.
* Global Justice headquarters, and several of Drakken's lairs, in ''WesternAnimation/KimPossible'', which also has a twist on the trope: Frugal Lucre's lair [[BasementDweller in his mom's basement]]. Also, a few of the locations where Drakken raids are themselves underground bases. Case in point, the episode where he steals some {{Hypno Trinket}}s had him raiding a base in the ColdOpening that was built underneath a desert, and [[AllDesertsHaveCacti a conspicuous cactus]] acted as a card key scanning device to grant entry.
* Perry The Platypus has one underneath ''WesternAnimation/PhineasAndFerb'''s house, and the rest of the [[FunWithAcronyms OWCA]] base seems to run beneath all of the Tri-State areas. ''All'' of it.

* In ''WesternAnimation/TheSimpsons'', a wealthy businessman and supervillain Hank Scorpio has an underground base with some sort of nuclear-powered ray gun in it, plus a laser for cutting spies in half. It also has a snack vending machine with a [[ArsonMurderAndJaywalking touchy dollar bill acceptor]].

* ''WesternAnimation/SuperFriends'': In the 1973-74 episode "The Fantastic Frerps", King Plasto has one as his headquarters, including a storage room for his Frerp eggs and a Frerps Arena for creating the eggs.

* Syndrome has an absolutely awesome underground base in ''WesternAnimation/TheIncredibles'', complete with the '50s-'60s Tiki/Googie/Art Deco look. Eggshell people-movers, yeah! Don't forget, it was built ''inside an active volcano''.

* In ''LightNovel/Overlord2012'', the VillainProtagonist and his forces are headquartered in the Great Tomb of Nazarick, a ten-level complex so big that one of those levels contains an entire forest and a colosseum, and another (the residential area) is basically a small town unto itself.

* ''Literature/TheWitchOfKnightcharm'': A Scholomance student named Lauren tells Emily that the school is a facility in a big underground cave, as per the [[Myth/TheScholomance traditional myth]].

* ''Film/ScreamersTheHunting''. The eponymous {{Killer Robot}}s are made in automated factories beneath the surface. The characters have an OhCrap reaction when they enter a shut-down factory and see just how ''big'' it is. Of course, someone [[IdiotBall inevitably does something stupid]] to cause it to power up again...
* ''WesternAnimation/SecretMagicControlAgency'': The SMCA's headquarters are located in a massive cavern beneath a hair salon. Bridges connect different areas and there are hot air balloons seen inside.

* SHADO Headquarters in ''Series/{{UFO}}'' is located beneath a film studio. Think about it...

* Literature/TheThrawnTrilogy has the Mount Tantiss facility on Wayland, a massive complex where The Emperor keeps all the potentially useful bits of tech he's collected.

* SuperheroSchool Whateley Academy in the Literature/WhateleyUniverse has ''extensive'' underground stuff. Powers testing, deviser workshops, arenas, you name it. And that doesn't even cover the highly dangerous sewer system there. Lampshaded by mentions that they now have to be quite careful where and how much they dig, in order to avoid having the above-ground structures fall into a sinkhole.

* Creator/JRRTolkien was big on these, for good, bad, and ambiguous guys.
** In ''Literature/TheHobbit'', you have dwarf Kingdom Under-The-Mountain in the Lonely Mountain (pwned by Smaug the dragon). In ''Literature/TheLordOfTheRings'' you have Khazad-dûm (Moria), the ancient dwarven country under the Misty Mountains. Dwarves in general prefer to live in these sorts of places. Even the Petty-dwarves have a hall under a large hill in ''Literature/TheChildrenOfHurin''.
** Morgoth, the BigBad of ''Literature/TheSilmarillion'' had [[{{Hell}} Utumno]], which amounted to an underground ''country'', plus Angband (whose excavation produced enough refuse and slag to pile into an enormous mountain). Both were filled with vast mines, dungeons, torture chambers, and other... pleasant things.
** Elves vastly prefer to live above-ground, but oddly enough a few groups also built/excavated underground fortress-cities.
** ''The Silmarillion'' features Nargothrond (destroyed by Glaurung the dragon) and Menegroth -- both were built with dwarven assistance, and are very beautiful inside. ''The Hobbit'' also mentions Nargothrond's Noldor under the confusing appellation "deep elves" -- it refers to their "deep" knowledge rather than an established habit of living underground, which no elves demonstrate.
** ''The Hobbit'' also features the underground-dwelling Wood Elves of Mirkwood, who probably got the idea from Menegroth.
** The Dead Men of Dunharrow lived in an elaborate system of caves in the mountains (when they were still alive, presumably) and were still there 3,000 years after they'd died.
** Hobbits, despite their general preference for underground living, ''don't'' have these. Their humble, homebody, rural-England aesthetic doesn't go with busy cities or ancient works of peerless engineering.

* The [[EverythingsBetterWithDinosaurs Pangea Alliance]] in the ''Franchise/MassEffect'' story ''Fanfic/MesozoicEffect'' use these to the point where they don't actually build permanent structures on the surface of their planets. They were originally needed to house the millions of dinosaurs that were waking from their 65 million-year [[HumanPopsicle cryosleep]], but eventually started building them on other worlds because of their defensive potential.

* Wiki/SCPFoundation has a number of underground sites that contain artifacts, creatures, and locations that could [[TheEndOfTheWorldAsWeKnowIt burn/rewrite/exterminate the whole world and to an extent the]] ''[[TheEndOfTheWorldAsWeKnowIt universe]]'' if they were to be left unregulated. There is no known exact number of how many underground sites the Foundation has, but these sites could be located in a place where there is a high population density, simply masquerading as an ordinary business, or just located in a simple, well-known army base.

** The Ministry of Magic is completely underground. It can be reached via elevator telephone booth, flushing down magic toilets (no joke), Apparation or Floo powder. Like the Great Hall's sky ceiling, the windows are enchanted to allow daylight to filter in.

* Literature/TheThrawnTrilogy has the Mount Tantiss facility on Wayland.

* ''Manga/{{Doraemon}}'': One of Doraemon's future gadgets allow instant creation of one of these. It can be big enough to become a city of its own, which Nobita then exploit to create his own dictatorship (PlayedForLaughs). However, ''Anime/DoraemonNobitaAndTheKnightsOnDinosaurs'' deals with the sinister encounter with LizardFolk when Nobita and co DugTooDeep...

** The Island of Bardos. Dr. Hell set his first base in the subterranean mazes of that island, building all what he needed for his SuperVillainLair: a war room for planning strategies, private chambers for his CoDragons, barracks for his {{Mook}}s, several hangars, laboratories to build weapons, HumongousMecha and cyborgs, training fields for his troops and {{Robeast}}s, his throne room...

** ''Anime/GreatMazinger'': Mykene were a civilization had lived underground for millennia, so their entire empire -- an intricate network of caves and caverns -- was an Elaborate Underground Base.
* Jaburo of ''Anime/MobileSuitGundam''. As the Earth Federation's military headquarters, it is ''enormous'', having easily enough space for a small city, multiple war factories, and docking space and retractable launch pads for at least a dozen spaceships at once. It’s located beneath the South American jungle, buried so deep as to be impregnable to nuclear weapons, which is why the Principality of Zeon attempted to [[ColonyDrop drop a space colony on it]] instead. Granted that it's only seen in a few episodes of the original series before being [[SelfDestructMechanism blown away]] in ''Anime/MobileSuitZetaGundam'', but it does get additional screentime in ''[[Anime/MobileSuitGundam0083StardustMemory Stardust Memory]]'' and ''[[Anime/MobileSuitGundamMSIGLOO MS IGLOO]]''. It's long-forgotten ruins also make a cameo in the finale of ''Reconquista in G''.

* Numerous Galactor bases on ''Anime/ScienceNinjaTeamGatchaman'' fall under this heading. By extension, enemy bases on the Americanized versions.

* ''Anime/SuperDimensionFortressMacross''/''{{Anime/Robotech}}'' has an underground base in Alaska (possibly in the site of the real life Elmendorf AFB), armed with the ''{{BFG}}'' of [[WaveMotionGun Wave Motion Guns]]. Incidentally, secondary ''Anime/{{Macross}}'' sources list four other identical bases being built when the Zentradi launch the final attack, one of them in the same area of [[Anime/MobileSuitGundam Jaburo]].

** ''ComicBook/RedRobin'': Tim Drake is able to build an underground garage, gym, small lab and workshop for experimenting and making new tech and first aid/medical room beneath the old theater he renovated to live in. Fabian Nicieza and Marcus To stated the only reason it was so elaborate is that the fast approaching reboot meant they'd never have to try and justify why he could get away with so much construction without blowing his secret ID in story.
** In ''ComicBook/TheAttackOfTheAnnihilator'', Supergirl builds an whole underground base for ComicBook/{{Batgirl}} beneath the streets of Gotham, containing a garage, an armory, a computer and more.

* In ''ComicBook/GothamCityGarage'', ComicBook/{{Supergirl}}, ComicBook/{{Nightwing}} and ComicBook/{{Catwoman}} break into a secret facility built by ComicBook/LexLuthor underneath a mountain where he fabricates his army of robotical enforcers.

* ''ComicBook/SonicTheHedgehogIDW'': After the Restoration's headquarters is destroyed during the [[ZombieApocalypse Metal Virus Saga]], the ''Test Run'' arc reveals that they've built a new facility beneath the ruins of the old one. Accessible through hidden elevator, it contains a command center, computer labs, a machine shop, and a central area that's designed like a mall.

** During the Silver Age, ComicBook/LexLuthor's "Luthor's Lairs" numbered in the hundreds, and could be found anywhere. At least one of them lasted until the 30th Century, showing up in a ''ComicBook/LegionOfSuperHeroes'' story where the outlawed Legionnaires make use of it to not only get new outfits again, but find out [[MassHypnosis what caused the populace to turn against them]].

'''Socrates:''' Imagine a super villain living in a studio apartment in southeast central L.A. I wonder if they could afford the rent.

* ''Fanfic/EvaSessionsSomeplaceVastAndDry'': The NERV Evangelion Center originally started out as an conventional above-ground research center, before gradually transitioning most of it facilities to the canonical underground [=GeoFront=] to better protect them from attack by the Others. In this case, the NERV [=GeoFront=] is an genuine achievement of human civil engineering, [[spoiler:rather than the canonical repurposing of the buried remains of the object that [[{{Panspermia}} brought life to earth]].]]
* ''Fanfic/TalesOfTheOtherverse'': After leaving the Otherverse and settling in another reality, [[ComicBook/{{Supergirl}} Kara]] and ComicBook/{{Rogue}} set up their new Fortress in Colorado. Above the ground it looks like a quaint, lonely one-story ranch sitting in the middle of the wood... and above a vast network of caverns housing a grand complex built in the rock.
-->This Fortress would be their home... and from the outside it would appear to be no more than that: a truly elaborate home built in the seclusion of the wood.\\

* Syndrome has an absolutely awesome underground base in ''WesternAnimation/TheIncredibles'', complete with the 50's-60's Tiki/Googie/Art Deco look. Egg shell people-movers, yeah! Don't forget, it was built ''inside an active volcano''.

* ''Film/TheAvengers1998''. Sir August's underground base, which is on an island in the Thames in London.

* The majority of ''Film/DayOfTheDead1985'' takes place in a vast bunker as the scientists attempt to find a cure for zombies. Less elaborate that most other examples but it gets bonus points for being a real place; it was a mine that was converted for "long-term storage facility for important documents" which is the stuff Ben is looking through in the actual film.

* ''Film/JamesBond'' has very few of these, despite the series being ridden with cartoon villains and conspirators. The closest they ever got were the hollowed-out volcano complex in ''Film/YouOnlyLiveTwice'' and Drax's Amazon launch facility in ''Film/{{Moonraker}}''.

* Zion in ''Film/TheMatrix'' that is also a full blown city.

* ''Film/TheSantaClause'' franchise has the entire North Pole operation for Santa Claus under an ice pack in the North Pole, large enough to contain the entire Elf village to look like a surface settlement (in Canada, according to the third movie). It remains hidden because Santa and the elves have various strategies to hide it from the outside world. The rest of the world just sees the ice-cap and preserves the Secret of Santa.

* ''WesternAnimation/SpiderManIntoTheSpiderVerse'': The Peter of Miles' universe has one underneath Aunt May's shed, accessed by an elevator, where he keeps alternate costumes, a computer, lab, and diagrams of criminal connections. Peter B. is noticeably jealous of this, as his base back home just consists of the garden shed itself.

* ''Film/UndercoverBrother''. The BROTHERHOOD has an extensive base located beneath a barber shop.
* In ''Film/X2XMenUnited'' the underground base becomes a plot element when the SpySatellites actually detect the CoolShip in its hangar underneath the SuperheroSchool. William Stryker uses this evidence to convince the President to okay a commando strike on the school, secretly to further his plan to wipe out all mutantkind. Stryker's also got an Elaborate Underground Base of his own.

* The Yeerk Pool in ''Literature/{{Animorphs}}'' spans under an entire city. [[PuppeteerParasite Yeerks]] need to return there every three days to exit their hosts and absorb the radiation they need to survive, and said hosts are caged in the meantime. There's also enough room for several spaceships and storage areas.

* The titular "Big Four" in the Hercule Poirot novel ''Literature/TheBigFour''. It's under a mountain in Italy, where the the final confrontation between Hercule and (three of) the Big Four takes place.

* A similar rationale to Wonka's stands for the enormous set of underground tunnels built by the deep-down dwarfs in Ankh-Morpork in Creator/TerryPratchett's ''Literature/{{Discworld}}'' novels. By digging under the city, they can create their own dwarfs-only authentic dwarf mine under the city, unbeholden to city law or city rents. (In regions with larger dwarfish populations, there really ''is'' a separate "surface law" and "deep law".) After the events of ''Literature/{{Thud}}'', the deep-downers are thoroughly discredited and Lord Vetinari appropriates their delve for the city government, possibly as the basis of a future Ankh-Morpork subway system. Notably, Commander Vimes actually realizes the "dirt has to go somewhere" problem, and realizes the extent of the digging when he has his Disorganizer look through the gate reports for an increase in garbage leaving the city.
** how much actual digging was required is debatable, in that what Ankh-Morpork is built on is largely Ankh-morpork. The current city is just the top level of several layers of older buildings and construction, which over the generations have sunk, buried, or just been built over so many times that it it is a whole warren of passages and compartments, with old streets ending up as sewer tunnels, and old shops now serving as the (often unknown) basements, or subbasements to current buildings.

* Dénis Lindbohm's ''Frostens barn'' (''Children of the Frost'', given the context of the story) features this trope as the home of the surviving remnants of humanity and their descendants, with them living in an increasingly sprawling set of constructions under the [[CreatorProvincialism Scandinavian Mountains]]. In story, more installations were supposed to be built... but they were either unfinished or sabotaged when World War III came.

* The sapient rats from ''Literature/MrsFrisbyAndTheRatsOfNIMH'' built themselves a MouseWorld version of this trope under the farm. No actual AppliedPhlebotinum is present by ''human'' standards, but by the standards of other animals it's a regular MadScientistLaboratory.

* Chrysalis Base from ''Literature/StarTrekTheEugenicsWars'' is a giant underground research facility with labs, a nuclear reactor, an underground garden and even several classrooms. Great lengths have been taken to make it aesthetically pleasing and a nice place to live to the scientists there.

* In Creator/KimNewman's short story "Literature/{{Swellhead}}", the ghostly remains of the ElaborateUndergroundBase of a supervillain from an AlternateUniverse is beginning to seep into our world with disastrous consequences. The difficulties of building such a lair without elaborate funding or anyone knowing about it is lampshaded at one point (and is the clue to its nature).

** ''The Silmarillion'' features Nargothrond (destroyed by Glaurung the dragon) and Menegroth -- both were built with dwarven assistance, and very beautiful inside. ''The Hobbit'' also mentions Nargothrond's Noldor under the confusing appellation "deep elves" -- it refers to their "deep" knowledge rather than an established habit of living underground, which no elves demonstrate.

** S.H.I.E.L.D. has a number of underground bases and facilities, the main example being the Playground, which acts as their main headquarters from the end of the first season until its destruction midway through the fourth. As Coulson is reconciling with another branch, he uses this as a selling point towards peace.

** Season 5 features the Lighthouse, a top secret bunker created by S.H.I.E.L.D. in the 70's in case of nuclear war. It's so big and so well designed that in a BadFuture where [[EarthShatteringKaboom the Earth has shattered]], it functions as a perfectly habitable and self-sustaining space station.

* The Temple of the Cardinal Witches from ''Series/EmeraldCity''. The visible part looks like a fairly modest chapel, but beneath it there is a truly massive chamber, hundreds of times larger, where the spells of all the deceased witches are kept in jars. In [[Recap/EmeraldCityS1E10NoPlaceLikeHome "No Place Like Home"]], [[spoiler:Dorothy either destroys or damage it heavily with the stone giant's sword in order to stop Glinda and her witches]].

* In ''Series/{{Helix}}'', isolated research base Arctic Biosystems has ''several'' subterranean levels, the depth and extensiveness of which initially jar the CDC team sent to investigate there.

* M.I. 9 has an Elaborate Underground Base concelaed beneath St Hope's School in ''Series/MIHigh''. Given it houses only three operatives and their handler, it does seem somewhat like overkill.

* ''Series/OddSquad'': Most Odd Squad precincts' Headquarters, including Precinct 13579's, are situated deep underground. "Fistful of Fruit Juice" reveals that the idea to have underground Headquarters was the work of Big Red, a citizen of Oprah's hometown who wanted to thank her for retrieving his stolen mailboxes and decided to dig the [[TubeTravel tube system]] as a result. The Headquarters vary by precinct, but most of them have laboratories for the Scientists, North and South Control Rooms for the Security agents, and numerous rooms that range from practical (the Bedroom) to downright absurd (the Potato Room). The only aversion is the Arctic Odd Squad precinct's Headquarters, which is aboveground and is more low-budget than the Headquarters commonly seen, with a smaller lab area (which is useless considering the precinct doesn't use gadgets), a couple tables for a makeshift Breakroom, and a small pool filled with plastic balls.

* ''Franchise/PowerRangers'' uses this quite often. Some seasons, such as the original, simply imply it, while others are more blatant about it. The fifteenth season, Operation Overdrive, commonly does a cutaway to the base by showing the aboveground mansion, and then dropping the camera via CGI through several layers of planetary crust. For added hijinks, the Rangers in this season are implied to be sliding down kilometer-length fireman poles to reach said base. And on top of that, they have ''three'' HumongousMecha ''and'' a CoolShip hidden inside.

** The Genii of ''Series/StargateAtlantis'' act like SpaceAmish while actually living in these. Their true nature [[ContinuityDrift gradually becomes]] one of the worst-kept secrets in galaxy.
* ''Series/Stargirl2020'': The Injustice Society operate out of a bunker secreted in the heart of a TunnelNetwork running underneath Blue Valley, Nebraska. At the very least, it contains a central meeting room, [[MadScientist Dragon King's]] laboratory, and a staging ground for building [[MindControlDevice Project New America]]. It's revealed later that it was built by the founders of the town long before the Injustice Society ever arrived; the Injustice Society specifically chose the town because they learned of the tunnels and figured it would make a good hiding place.

* In the ninth episode of ''Series/StrikeBack: Project Dawn'', Scott and Stonebridge find their way into a system of Cold War-era underground bunkers, which the BigBad Latif was using as his base. Among the amenities are various storage, manufacture and testing facilities for WeaponsOfMassDestruction, which Latif had used in the development of his VX distribution system. A number of corridors are shown that could fit a tractor-trailer, and satellite scans indicate that the system is about 50 kilometers across and forms a five-point star.

* The Ultra Garrison base in ''Series/UltraSeven'' is located 18 stories down. This is PlayedForDrama in "Challenge at -140 Degrees", when a power outage and a ColdSnap caused by aliens threatened to kill a crew of 300 people inside while TheHero is stranded outside, unable to transform.

* British puppet character Roland Rat was originally supposed to live in the sewers beneath King's Cross railway station. In ''Series/RolandRatTheSeries'' this suddenly became "the Ratcave"; an Elaborate Underground Base containing living quarters, a talk show studio and a reception area, and accessed from a hidden lift in a workman's shelter outside the station.

** In the 5th ed. adventure book ''Waterdeep: Dungeon of the Mad Mage'', the titular mad mage Halaster Blackcloak has his home ''Undermountain'' built into the fallen underground dwarf kingdom of Melairbode. This underground base is so extensive that it has several different realms which are only accessible by special dimensional gates as well as a NighInvulnerable guest castle made of stone, glass, crystal and adamantite.
* The Jadeborn in ''TabletopGame/{{Exalted}}'', being the game's rough equivalent of dwarves/elves/gnomes, built underground cities, nations, military bases, factories, incomprehensible giant artifacts, and everything else an entire civilization of genius-craftsmen-artificers-inventers-engineers could produce over millennia of flourishing. In the Second Age their world-spanning underground empire has long since crumbled, but their remaining cities are still vast and elaborate and thoroughly underground.
* Alpha Complex from ''TabletopGame/{{Paranoia}}'' is usually an elaborate underground warren with all the super-science facilities you could ever need. [[note]]Then again, continuity has never been a big deal in ''TabletopGame/{{Paranoia}}'' so it can be a a domed city, underwater, whatever the GM desires.[[/note]]

* The dwarves of ''TabletopGame/{{Warhammer}}'' live in huge undergound cities, following the example set by Creator/JRRTolkien. And the [[RodentsOfUnusualSize Skaven]] live below those in big cities and tunnels that span every continent.
* ''TabletopGame/Warhammer40000'' gives us the planet of Calth in the Ultramar sector, where there are bases, cities, and agricultural communities built up in the planet's massive cavern system, because the sun is deadly. Necron tomb complexes also qualify.

* The moonbase setting of ''VideoGame/{{Bioforge}}'', complete with hangar bay, cryogenics lab, prison, defense tower, medical experimentation lab.

* The whole of ''VideoGame/BreathOfFireDragonQuarter'' takes place in a geofront like super cave.

** ''[[VideoGame/TheElderScrollsIIIMorrowind Morrowind]]'' has dozens of caves and grottos, some of which get quite elaborate, and are usually home to smugglers, bandits, or worse. Dunmer Ancestral Tombs and the afore-mentioned Dwemer ruins are also typically built into the ground.

** ''[[VideoGame/TheElderScrollsVSkyrim Skyrim]]'' continues the tradition of having countless smuggler/bandit/necromancer/etc. hideouts in the form of underground caves and ruins. Once again, many get extremely advanced. This is especially true of the old Nordic burials, which are complete underground ruins that can reach the size of full blown cities. Additionally, the Dwemer ruins return in full force with plenty of great examples, many of which have been taken over by their former SlaveRace, the Falmer. The Falmer are also shown to be capable of constructing elaborate networks of suspended bridges and platforms.

** ''VideoGame/Fallout1'' had the Glow, the Mariposa Military Base and the Brotherhood's Lost Hills HQ.
** ''VideoGame/Fallout2'' had the Sierra Army Depot and the Hubologist base. The Brotherhood bunkers in the Den, NCR and San Francisco might also count.

** ''VideoGame/FalloutTacticsBrotherhoodOfSteel'' had the Brotherhood bunkers and Vault 0 which was simply the Cheyenne Mountain Complex coverted into an even larger facility.

* ''VideoGame/FinalFantasyV'' had the Catapult, an underground/underwater base of LostTechnology. Among other things, it features an airship docking bay, a teleporter and a ship-sized elevator to the sea surface. And the icing on the cake? It's ''yours'' now.

** Armacham Technology Corporation established the main facility for the Origin Project in an old military-industrial complex, and built the entire facility deep underground. Emphasis placed on the past tense, what with the explosive ending of the first game.

** [[spoiler:In the end it takes an [[ItsTheOnlyWayToBeSure underground nuclear bomb]] to eliminate any remaining witnessess and all alien forces still inside the facility.]] Though that event might be [[CanonDiscontinuity non-canon]] and is neither mentioned by the games from the main series developers, nor does it fit with the details revealed in later games.

** ''VideoGame/Halo3'' -- the second level takes place in Crow's Nest, an "old 20th century" military base inside Mount Kilimanjaro, which has been re-activated after the Covenant took over Earth. This base comes fully equipped with a hangar bay, hidden landing pads, big imposing steel doors and a war room, complete with big screens and BridgeBunnies.

* ''VideoGame/KuriKinton'': The game is set inside of a huge underground base full of enemies and bosses. The PlayerCharacter goes there to rescue a senior policeman and his daughter.

* In the first ''VideoGame/MegaManZero'' game, the LaResistance's base is located underneath an abandoned city. While the "base" itself is run-down, there are still some machinery functioning there, like an elevator and a teleporter. The base, after numerous attacks, was completely abandoned by the group in favor of a ''more'' elaborate, newer base (although it's not underground anymore).

* The entirity of ''VideoGame/{{Overblood}}'' takes place in one.

* ''VideoGame/Rayman3HoodlumHavoc'': The Hoodlum Headquarters area as well as the majority of the Desert of the Knaaren level, the latter potentially justified by the fact it's a natural cave system.. Doesn't explain why it also has a mini TempleOfDoom inside it too though.
* In ''Franchise/ResidentEvil'', seemingly every building in Raccoon City, or in the forests surrounding it, has at least one well hidden elevator leading into one of the multiple underground Umbrella Corporation labs (which makes sense when you consider that Umbrella essentially owns and runs the city).

** TheIlluminati operate from one of these in Brooklyn: known as the Labyrinth, it can only be entered via hidden entrances concealed in the sewers and cellars of the area, and is heavily guarded against intrusions by non-Illuminati personnel. Among other things, it features testing chambers, a MadScientistLaboratory, a vast server farm, a colossal pyramid-shaped concourse, and a lot of areas that are officially off-limits to the player -- unless you've made a huge mistake.
** The [[PathOfInspiration Morninglight]] have a "clubhouse" hidden under the Tokyo docks, intended to lure in the best and the brightest of potential recruits. Initially, it appears to only consist of an underground social club, with a bar, video arcade, swimming pool, shooting range and gym... but for those who've been earmarked for greater things by the Morninglight higher-ups, a [[TrackingChip chip]]-activated door reveals the complex also features a ''massive'' stadium-sized temple, complete with marble floors, sculpted columns, a colossal domed ceiling, and artworks. Plus, it's also got a cafeteria and offices for the Morninglight missionaries. [[spoiler: Of course, by the time you get there, the place has been overtaken by the Filth, and the members have either been infected, killed, or forced to flee.]]
** As if it wasn't enough to own an EvilTowerOfOminousness big enough to give the Burj Khalifa an inferiority complex, the Orochi Group have a gargantuan factory hidden beneath their Tower headquarters. Known only as the Manufactory, this area -- visited only as a dungeon mission -- appears to be the size of a small city, and can easily churn out enough drones, tanks and HumongousMecha to clog the streets of Tokyo if need be.

* ''VideoGame/TeamFortress2'' has many maps with partial subterranean base setups (most notably, the basements of 2Fort) and the occasionl map which takes place entirely underground, such as Junction and Nucleus (despite the latter's open-air mid point, implied to be the mouth of a dormant volcano).

** The Dark Iron Dwarves have their own underground base in Blackrock Mountain. Technically so does the Dark Horde and Nefarian, since their towering base is built ''inside'' a volcano's cone.
** The Defias Brotherhood has the extensive Deadmines, a combination mining facility, smelter, sawmill, and wetdock.

** After taking the step from "overzealous faction leader" to "raving madman", Garrosh Hellscream commissioned a massive underground fortress, complete with barracks, laboratory, factory, beast pens, treasure vault, and ginormous throne room, built underneath the orcish capital of Orgrimmar. Only one quarter of the Siege of Orgrimmar raid actually takes place in the aboveground portion of the eponymous city (although some of it is in Pandaria); the bulk of it takes place in Garrosh's bunker.

** The Firaxis remake enhances base-building by allowing you to determine where to dig, which facilities to place on which level (the original only had one level). It's all the more important here because you're limited to one base, as opposed to the original, where you could have a base on each continent if you wished.

* ''VideoGame/GrimDawn'' has Warden Krieg's ridiculously large basement that stretch for hundreds of meters. It spawns two levels with a cellar, tunnels, labs, storerooms, jail cells and living quarters just to name a few. It also has some [[GiantSpider giant spiders]] and various beasts that are are hostile to the Aetherials and you.

* The military base where the [[HalfHumanHybrid Chio]] were created in ''Webcomic/{{Follower}}'' is one of these. Aside from the hangars, most of the base appears to be underground.

* ''Webcomic/TimesLikeThis'': It may ''technically'' be an Elaborate Underground Base, since it's run by a multination secret-service consortium, but [[http://timeslikethis.com/index.php?id=443 Paratopia]] is actually an underground Club Med-type getaway roughly the size of Delaware.

* Pelvanida from ''Roleplay/DarwinsSoldiers'' is an underground military research base. It is not really "hidden" per se, though, as quite a bit of above ground infrastructure is present.
* ''Podcast/RandomAssault'': The Random Assault headquarters, which is an underground skyscraper-mansion consisting of many rooms made from all sorts of things, even garbage. The facade above ground is an old, abandoned Circuit City building with the RA logo on the side, as Circuit City buildings are red cubes, very much like the show's logo. Often, guests will be brought to the mansion with a bag over their head so they can't find their way back. The hosts don't live there, either. They use [[PortalNetwork a series of rifts]] to travel to the mansion from their respective living places around the world.
* Wiki/SCPFoundation has a number of underground sites that contains artifacts, creatures, and locations that could [[TheEndOfTheWorldAsWeKnowIt burn/rewrite/exterminate the whole world and to an extent the]] ''[[TheEndOfTheWorldAsWeKnowIt universe]]'' if they were to be left unregulated. There is no known exact number of how many underground sites the Foundation has, but these sites could be located in a places where there is a high population density, simply masquerading as a ordinary business, or just located in simple, well-known army base.

* Gummi Glen in ''WesternAnimation/AdventuresOfTheGummiBears''. This version distinguishes itself by its surprisingly realistic take of an underground structure of such extraordinary complexity in medieval times. Namely, the Glen requires a sophisticated infrastructure like a mechanical ventilation system to maintain air quality while the Gummis have a variety of maintenance concerns like water levels, plant growth and erosion of the surrounding ground.

* In the ''WesternAnimation/ChipNDaleRescueRangers'' pilot, Aldrin Klordane had turned a cave conveniently placed underneath the Federal Gold Reserve into his own Elaborate Underground Base which not only has a diagonal monorail, but even a real railroad connection.

* ''WesternAnimation/{{Dangermouse}}'' lived in an underground base in postbox on Baker Street in London, the same road as Sherlock Holmes.

* ''WesternAnimation/JackieChanAdventures'' had the underground base of Section 13 in San Francisco. Said organization was where the main characters would live along with being the location of what ever {{MacGuffin}}s were being [[GottaCatchThemAll collected]] that season. Could be reached via a phonebooth elevator or "the stairs".

** "The Dreadful Doll" has an arms and submarine base being built under the surface of the island.

* Global Justice headquarters, and several of Drakken's lairs, in ''WesternAnimation/KimPossible'', which also has a twist on the trope: Frugal Lucre's lair [[BasementDweller in his mom's basement]]. Also, a few of the locations that Drakken raids are themselves underground bases. Case in point, the episode where he steals some {{Hypno Trinket}}s had him raiding a base in the ColdOpening that was built underneath a desert, and [[AllDesertsHaveCacti a conspicuous cactus]] acted as a card key scanning device to grant entry.
* Perry The Platypus has one underneath ''WesternAnimation/PhineasAndFerb'''s house, and the rest of the [[FunWithAcronyms OWCA]] base seems to run beneath all of the Tri-State area. ''All'' of it.

* In ''WesternAnimation/TheSimpsons'', wealthy businessman and supervillain Hank Scorpio has an underground base with some sort of nuclear-powered ray gun in it, plus a laser for cutting spies in half. It also has a snack vending machine with a [[ArsonMurderAndJaywalking touchy dollar bill acceptor]].

* Underground command-and-control centers started getting popular sometime after UsefulNotes/WorldWarI, and much more so after nuclear weapons and [=ICBM=]s. [[http://www.greenbrier.com/site/bunker.aspx Greenbrier Resort]] was the site of a [=US Congressional=] command center for 30 years, until [[http://www.washingtonpost.com/wp-srv/local/daily/july/25/brier1.htm a Washington Post reporter exposed its existence in 1992.]] The Cheyenne Mountain Complex in UsefulNotes/{{Colorado}} is quite famous as the "brain" of [[http://en.wikipedia.org/wiki/NORAD NORAD]] ([=NORth-american Air Defense=]), [=SAC=] (Strategic Air Command, bombers and land-based [=ICBM=]s) and the US Space Command (more to do with satellites, though). The latter two are now defunct, absorbed into other organizations. NORAD is now based at Peterson Air Force Base (a conventional above-ground air force base nearby), but keeps Cheyenne Mountain on warm standby.

*** There's supposedly an entire [[http://en.wikipedia.org/wiki/Moscow_Metro_2 secret subway system under Moscow]], ''bigger'' than the regular one and buried up to 200m underground, linking numerous important buildings and providing means for movement and evacuation of [=VIPs=]. Though, if the most popular purported map of the system is to be believed, it's only larger in a sense that some of its tunnels are significantly longer than the ones of the normal Metro -- one of them supposedly reaches Vnukovo airport. Otherwise there are few of them, and the tunnels and stations are narrow, undecorated and spartan. The Metro 2 makes a prominent appearance in ''Videogame/{{Metro 2033}}'', where it is allegedly has vaults full of pristine military equipment.

*** Or not. Mantaining any large underground object would require much better logistical capabilities that could be provided by third-class narrow mountain road and long-defunct (and partially dismantled) railway, which seems to be the only roads near Yamantau.

** Similar to the Greenbrier Resort are the Canadian [[http://en.wikipedia.org/wiki/Diefenbunker Diefenbunkers]]
** A few shots in the movie ''Film/WarGames'' showed the actual Cheyenne Mountain complex. The NORAD room in that was a mock-up (the most expensive movie set ever at that time) and far more snazzy than the real one. This was due to the film-makers having insufficient security clearance for the real one.
*** The Second-In-Command of NORAD is a Canadian (it's NORTH AMERICAN Air Defense, not American Air Defense) -- and yet in all the movies set in Cheyenne Mountain there is nary a Canuck in sight.
** Also, Cheyenne Mountain is in ''Series/StargateSG1'' and ''Series/{{Jeremiah}}'' (This one has the benefit of being a real complex). In the original movie ''Film/{{Stargate}}'', the Gate was hidden in the fictional Creek Mountain complex -- also in Colorado, and to boot having recycled the Cheyenne Mountain entrance set from ''Film/WarGames''. The series retconned the Stargate's location without much fuss. To make Stargate Command, they added 2 fictional sub-floors to the real life Cheyenne Mountain Complex. The complex itself is real, the extra floors housing Stargate Command aren't. Though, in the real complex, there is a door marked Stargate Command in homage to the series (since it was BackedByThePentagon). It leads to a broom closet.

** Offutt Air Force Base is rumored to have an underground command center proof against anything short of a direct hit with a nuke. It's impossible to be certain, because those chambers are ''not'' on the Official Elementary School Field Trip tour, they're still in use. (UsefulNotes/GeorgeWBush did not fly to Omaha on 9/11 because he wanted steak for lunch...)

** London also had Churchill's Cabinet War Rooms under the Treasury building. Their existence was kept a secret until the 1980s, when they were renovated and opened as a museum.
* [[UsefulNotes/SwissWithArmyKnives Switzerland]] has built and maintained an extensive system of fortifications, tunnels, living facilities, and storage facilities, much of it underground or at least dug deep into mountains, called the National Redoubt, dating back to late 19th century. In the 20th century, they enhanced it such additions as underground/in-mountain hangars for their air force, and built reinforced highways that can function as backup runways when the planes emerge.
* The USSR had a secret underground submarine base on the Black Sea. It couldn't, however, fit the larger subs of TheEighties, and was subsequently decommissioned. In now houses a museum of the former base.

* UsefulNotes/NorthKoreansWithNodongs have a vast network of tunnels and bunkers crisscrossing their mountainous country, which houses most everything military-related, from bomb shelters to storerooms to arms factories and control centers, etc. Some of those bunkers conceals secret SAM installations, and some house the mobile launchers of their recently developed [=MRBMs=]/[=ICBMs=], where they could be kept out of sight [[DeathFromAbove and possible bombing raids]], but could be quickly brought out to bear. This alone makes a possible invasion a potential bloodbath of unimaginable proportions. They also had several underground tunnels built so their troops could surprise-invade South Korea when the time is right (or so the southerners think). In reality, the most those tunnels were used for was the spy insertion and retrieval.

** This is a common strategy for large university libraries - Firestone Library at Princeton University has three underground stories (all much larger than the above-ground footprint) housing more than 70 miles of shelves.
* The Cu Chi Tunnels in Vietnam are another great example, and are almost the archetype of the EUB.

** {{Conspiracy Theorist}}s [[EpilepticTrees speculate]] about the existence of [[FunWithAcronyms DUMB]], or Deep Underground Military Base. It doesn't sound any more sinister than your regular well-protected military base, except that it's supposedly run by your favorite conspiracy (TheIlluminati and ReptilianConspiracy being popular choice) and people are abducted and carried there for unspeakable purposes.
* Željava Air Base in former Yugoslavia is the world's largest underground ''Air Base''. While they still have overground runways, everything else is underground and has enough food, fuel and ammo to survive 30 days without outside intervention. It has been, alas, demolished.

* In London, the [[http://www.silentuk.com/?p=2792 underground railway]] linking Royal Mail facilities, now closed, but documented by urban explorers.

* Humans don't have a monopoly on this trope either; ants have been known to form some [[https://www.youtube.com/watch?v=lFg21x2sj-M fantastically complex underground structures]]. You think this one is impressive then the largest one know, under Hokkaidō, has an area of roughly 2.7 square kilometers.
* Allegedly, UsefulNotes/OsamaBinLaden's "command centre" in the caves of Tora Bora mountain was this, with reports of fully equipped hospitals, hydro-electric power stations, a hotel, a tank park, and facilities for 2000 men flying around prior to its capture by [=NATO=] forces during Operation Enduring Freedom. Turns out it was a system of natural caves, with a few small manmade connecting tunnels, housing for 200 men ''at most'', some middlingly sized ammunition depots, and rudimentary medical facilities run by TheDragon (Ayman al-Zahawiri is a qualified surgeon). Whilst possibly more impressive than usual guerilla hideouts, it hardly lived up to its hype.

* A non-military example is the Leas Cliffe Hall in Folkestone, Kent, a 700-seater theatre/performance venue and conference center. Built in the 1920's, the only obvious sign of its presence is a modestly sized pavilion and cafe on the promenade. However, go inside and follow the steps down. The theatre complex is actually built into the cliff -- a westerly extension of the White Cliffs of Dover -- and occupies several underground levels, with bars and terraces overlooking the English Channel. Elsewhere on this stretch of coast, the greater part of Dover Castle is a network of underground galleries and strongpoints built into the White Cliffs proper; it served as a major command centre in UsefulNotes/WW2, and its underground structure was greatly added to so as to protect it from German bombing and long-range artillery.

*** Many of Japanese island bases during UsefulNotes/WorldWarII featured an extensive system of underground fortifications based on both natural caves and man made tunnels -- Iwo Jima, Pelilieu, Saipan, etc.

* When the British started bombing the Germans' rocket works at Peenemunde in 1943, the entire manufacturing operation was moved to Mittelbau-Dora, a factory / concentration camp built in mountain tunnels in Thuringia. This was were the bulk of the V-1 and V-2 rockets were constructed. In contrast to the fanciful nature of the whole enterprise -- ''[[StupidJetpackHitler secret underground Nazi rocket base!]]'' -- the camp was a particularly brutal one, where one in three workers (about 20,000 in total) died... largely pointlessly, since it turns out untrained, starving and unenthusiastic slave workers aren't very good at making hi-tech stuff. In fact, more people died constructing and working in these factories than were killed by the weapons they manufactured.
* The ''Führerbunker'', where Hitler spent the last weeks of the war, was originally built to be a termporary air raid shelter. However, as the Allies pressed further into German territory, it was expanded into an improvised permanent shelter. By all accounts, it protected its inhabitants from the shelling outside.

* British puppet character Roland Rat was originally supposed to live in the sewers beneath King's Cross railway station. In ''Roland Rat: The Series'' this suddenly became "the Ratcave"; an Elaborate Underground Base containing living quarters, a talk show studio and a reception area, and accessed from a hidden lift in a workman's shelter outside the station.

* Underground command-and-control centers started getting popular sometime after UsefulNotes/WorldWarI, and much more so after nuclear weapons and [=ICBM=]s. [[http://www.greenbrier.com/site/bunker.aspx Greenbrier Resort]] was the site of a [=US Congressional=] command center for 30 years, until [[http://www.washingtonpost.com/wp-srv/local/daily/july/25/brier1.htm a Washington Post reporter exposed its existence in 1992.]] Cheyenne Mountain, Colorado, is quite famous as the "brain" of [[http://en.wikipedia.org/wiki/NORAD NORAD]] ([=NORth-american Air Defense=]), [=SAC=] (Strategic Air Command, bombers and land-based [=ICBM=]s) and the US Space Command (more to do with satellites, though). The latter two are now defunct, absorbed into other organizations. NORAD is now based at Peterson Air Force Base (a conventional above-ground air force base nearby), but keeps Cheyenne Mountain on warm standby.

* ''Anime/NeonGenesisEvangelion'' has NERV setting up shop inside the [=GeoFront=], a massive cavern that is actually just the upper 11% of an even larger spherical cave, [[spoiler: which is actually the buried remains of the Black Moon, the object that [[{{Panspermia}} brought Lilith and life to earth,]]]] almost completely filled up with earth and rock debris. And going UpToEleven, Terminal Dogma is an Elaborate Underground Base built below another Elaborate Underground Base.

** UNATCO Headquarters is itself underground, with [[spoiler:an MJ-12 base]] beneath it. Yes, the game has an example of [[UpToEleven an underground base beneath another underground base.]]

* ''Manga/{{Doraemon}}'': One of Doraemon's future gadgets allow instant creation of one of these. It can be big enough to become a city of its own, which Nobita then exploit to create his own dictatorship (PlayedForLaughs). However, one of the movie deal with the sinister encounter with LizardFolk when Nobita and co DugTooDeep...

* During the Hydra arc of [[ComicBook/JMSSpiderMan JMS's run on Spider-Man]], Peter wonders how ComicBook/{{HYDRA}} can build one of these in New York while it's taken the city three extra months to finish a subway extension.

* ''Fanfic/DungeonKeeperAmi'' features this often and in diverse flavors. The Dungeons themselves, are a little more feudal, but Ami's underground bases just keep getting more elaborate and more DungeonPunk. Mecha? Check. Underground magical hudrophonics bays? Check. War Room? Check. SigilSpam? Check. Lacks a proper hangar for the [[{{CoolAirship}} airship fleet]], but one was actually an UnderwaterBase, and another an IslandBase...

* In ''{{Literature/Remember To Always Be Brave}}''there are four of these. Three out of those are scenes of gory battles throughout the course of the book.

* In ''{{Literature/Shatter Me}}'' Castle creates Omega Point, an underground city where people with gifts gather to plan a rebellion against the oppressive Reestablishment.

* On ''Series/{{The 100}}'', Mount Weather is an enormous underground bunker, used to house a small (but technologically advanced) community of people who can't survive on the radiation-soaked surface.

* The second season of ''Series/{{Space 1999}}'' saw the command team move from the above-ground "Main Mission" set to a "Command Center" located deep underground.

** In ''Series/{{Joe 90}}'' the BIG RAT was located in a secret underground facility beneath Professor [=McClaine=]'s house.
** In ''Series/{{Stingray 1964}}'', during alerts the entire ''city'' of Marineville can descend into a secure underground facility on hydraulic jacks. (Just in case anyone thought ''Anime/NeonGenesisEvangelion'' did that first...)

* ''TabletopGame/{{Warhammer 40000}}'' gives us the planet of Calth in the Ultramar sector, where there are bases, cities, and agricultural communities built up in the planet's massive cavern system, because the sun is deadly. Necron tomb complexes also qualify.

* In ''[[Videogame/GabrielKnight Gabriel Knight: Sins of the Fathers]]'', the voodoo cartel has a temple doubling as their headquarters [[spoiler:under Jackson Square]]. It's hinted to have been built in the 19th century when [[spoiler:the cathedral had to be rebuilt from scratch]]. Still, hiding a secret side project that big would take a lot from Marie Laveau's followers and clients.

** ''VideoGame/{{Halo 3}}'' -- the second level takes place in Crow's Nest, an "old 20th century" military base inside Mount Kilimanjaro, which has been re-activated after the Covenant took over Earth. This base comes fully equipped with a hangar bay, hidden landing pads, big imposing steel doors and a war room, complete with big screens and BridgeBunnies.

* In ''Videogame/{{Hitman 2016}}'', [[MadScientist Silvio Caruso]] has an entire laboratory filled with scientists and guards in a cave underneath his estate. It's justified as being built by the company he's working for since he's an agoraphobe who hates traveling.

* In the first ''Videogame/MegaManZero'' game, the LaResistance's base is located underneath an abandoned city. While the "base" itself is run-down, there are still some machinery functioning there, like an elevator and a teleporter. The base, after numerous attacks, was completely abandoned by the group in favor of a ''more'' elaborate, newer base (although it's not underground anymore).

** ''VideoGame/{{EarthBound}}'' has a huge base under Stonehenge in Winters.

* Naoto's dungeon in ''VideoGame/{{Persona 4}}'' is one of these.

* The Aperture Science Enrichment Center in ''VideoGame/{{Portal}}'' is located, per the [[AllThereInTheManual supplementary material]], in an abandoned salt mine in Cleveland, Ohio. ''VideoGame/{{Portal 2}}'' bizarrely retcons this to be in Upper Michigan, but also takes the player on an exploration of the true vastness of the place. Elaborate barely even begins to describe it: some parts of the game take place as much as ''four kilometers'' underground, and the player is treated to vistas of immense facilities stretching as far as the eye can see, constructed over a period of at least fifty years.

* ''VisualNovel/{{Virtues Last Reward}}''[[spoiler: takes place in one of these, but ON THE MOON.]]

* Jaburo of ''Anime/MobileSuitGundam''. As the Earth Federation's military headquarters, it is ''enormous'', having easily enough space for a small city, multiple war factories, and docking space and retractable launch pads for at least a dozen spaceships at once. It’s located beneath the South American jungle, buried so deep as to be impregnable to nuclear weapons, which is why the Principality of Zeon attempted to [[ColonyDrop drop a space colony on it]] instead. Granted that it's only seen in a few episodes of the original series before being [[SelfDestructMechanism blown away]] in ''Anime/MobileSuitZetaGundam'', but it does get additional screentime in ''[[Anime/MobileSuitGundam0083StardustMemory Stardust Memory]]'' and ''[[Anime/MobileSuitGundamMSIGLOO MS IGLOO]]''.

* ''WesternAnimation/AvatarTheLastAirbender''. The [[SecretPolice Dai Li]] had a underground base under a lake.