History Main / ElaborateUndergroundBase

** ''{{Thunderbirds}}'' of course had the Thunderbird hangars beneath Tracy Island.

* The Tracy Island of {{Thunderbirds}} could well be the TropeCodifier.

* ''WesternAnimation/AvatarTheLastAirbender'': the [[SecretPolice Dai Li]] had a undergound base under a lake.

** It continues in ''VideoGame/PokemonRubyAndSapphire'' and Emerald, with the Team Aqua and Magma bases.

* ''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.
** ''Franchise/SuperSentai'' used this in multiple series. [[Series/KyoryuSentaiZyuranger Zyuranger]], [[ChourikiSentaiOhranger Ohranger]] and [[Series/TokumeiSentaiGoBusters Go-Busters]] are prominent examples.

* ''Plan 7 of 9 from Outer Space''. In the {{Zeerust}} future of 2009, the SupervillainLair is a depthscraper "from the days when whole cities were built underground in fear of another atomic war."

To maintain PlausibleDeniability and hide from magical TV SpySatellites, any sufficiently powerful or advanced covert organization of heroes, villains, conspirators, or military personnel needs an ElaborateUndergroundBase to use as their headquarters and hide their AppliedPhlebotinum. AfterTheEnd, or in preparation for TheEndOfTheWorldAsWeKnowIt, openly known organizations may elect to move BeneathTheEarth as well. And it's a good location for a SupervillainLair.

The ElaborateUndergroundBase will generally have a [[TheWarRoom war room]], and may also include hangar space for HumongousMecha or a CoolStarship. Particularly large examples may be the size of [[UndergroundCity an entire city]], and might include hydroponics bays for growing food or even actual fields of crops lit by sun lamps. The larger sizes of ElaborateUndergroundBase frequently serve as an [[AdventureTowns Adventure Town]]; the smaller ones are frequently the setting for a BottleEpisode. If it was built during the ColdWar, it may be YeOldeNuclearSilo.

Particularly secretive organizations may hide their ElaborateUndergroundBase in the middle of a city, and include lots of elevators, trams, pneumatic tubes, and other means of transportation between the base and hidden chambers in buildings on the surface.

* ''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 almost completely filled up with earth and rock debris. And going UpToEleven, Terminal Dogma is an ElaborateUndergroundBase built below another ElaborateUndergroundBase.

** ''Anime/GreatMazinger'': Mykene were a civilization had lived underground for millennia, so their entire empire -an intrincate network of caves and caverns- was an ElaborateUndergroundBase.

* One of ''{{Doraemon}}''`s future gadgets allow instant creation of ElaborateUndergroundBase. 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 TheReptilians when Nobita and co DugTooDeep...

* ''PS238'', the school for children of superheroes, is in an ElaborateUndergroundBase beneath an ''actual'' elementary school.

* In ''Film/X2XMenUnited'' the underground base becomes a plot element when the SpySatellites actually detect the CoolShip in its hangar underneath the Mutant Academy. 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 ElaborateUndergroundBase of his own.

* In Creator/KimNewman's short story "Literature/{{Swellhead}}", the the ghostly remains of the ElaborateUndergroundBase of a supervillain from an AlternateUniverse is beginning to seep into our world with disastrous consequences.

* 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 ElaborateUndergroundBase 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 ''Series/StargateSG1'', Stargate Command functions as an ElaborateUndergroundBase that includes a functioning interplanetary wormhole (see "RealLife" example, below). In later seasons, the "Alpha Site", "Beta Site" and "Gamma Site" are all built as copies of the SGC on other planets.

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

* Xenon Base in ''Series/BlakesSeven'' was an ElaborateUndergroundBase owned by a VillainOfTheWeek. Upon his death, the heroes moved in and made it their base of operations for the remainder of the season. When you are a marginal band of outlaws facing a star-spanning empire, there is significant psychological comfort of being hidden under megatons of rock.

* OlderThanTelevision: The prototypical ElaborateUndergroundBase may well be Erik's lair under the Paris Opera in the various incarnations of ''ThePhantomOfTheOpera''.

* A few games have appeared where constructing an ElaborateUndergroundBase is a major aspect of the gameplay, notably:

** ''Project Origin'' takes it even further. The Auburn Memorial Hospital is a full-sized building constructed underground ''inside'' another ElaborateUndergroundBase. Wade Elementary has another ElaborateUndergroundBase beneath it. And that's before you get to the giant tram tunnels running through titanic chambers that include a Replica storage facility and massive maintenance area. Pretty much the entirety of Fairport is riddled with Armacham secret bases.

* In ''{{Thief}} II: The Metal Age'', the Cetus Project is run from Markham's Isle, a former pirate base taken over by the Mechanists. As you learn when you go there, the administration of the project is a bit complicated, but Markham's Isle certainly fits the IslandBase and ElaborateUndergroundBase tropes.

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

* The ''WesternAnimation/RoadRovers'' had an ElaborateUndergroundBase. It was strongly implied in at least one episode that it was the remains of a lab in Socorro, NM, that the Rovers' mentor ran.

* In SonicTheComic the Freedom Fighters use Kintobor's labtory containing living space, storage areas, monitoring equipment (which left plenty of screens on which to play videogames!), a hangar for the Freedom Fighters' biplane, and the mainframe of the Kintobor Computer itself. The Freedom Fighters also expanded the facility in light of their new status as guerillas, excavating further chambers for additional capacity. The most prominent of these was a prison block (less charitably, dungeon), and later Tekno's Workshop the home and workplace of Tekno the Canary.

The ElaborateUndergroundBase will generally have a [[TheWarRoom war room]], and may also include hangar space for HumongousMecha or a CoolStarship. Particularly large examples may be the size of an entire city, and might include hydroponics bays for growing food or even actual fields of crops lit by sun lamps. The larger sizes of ElaborateUndergroundBase frequently serve as an [[AdventureTowns Adventure Town]]; the smaller ones are frequently the setting for a BottleEpisode. If it was built during the ColdWar, it may be YeOldeNuclearSilo.

Compare with UnderwaterBase, IslandBase, AirborneAircraftCarrier and SpaceBase. See BeneathTheEarth for a related phenomenon, minus the AppliedPhlebotinum. May induce SigilSpam if the organization really loves their logo.

* TheIlluminati's Bavarian headquarters in ''{{Duumvirate}}'' is one of these. Parts of it are a couple of centuries old.
* David Wingrove's ''ChungKuo'' has a series of underground bases in the Alps, the only part of Europe that is not occupied by the City or its plantations

* Supervillain Doctor Impossible of ''SoonIWillBeInvincible'' has a base descending deep into the Earth: when he returns to it after his last defeat, the deeper levels are still intact. Also, his first base was dug down from the basement of an ordinary suburban house.
* SuperheroSchool Whateley Academy in the 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.

* The Alchemists' Guild in ''ASongOfIceAndFire'' has an elaborate underground Guildhall composed of a labyrinth of tunnels, cells, halls, and warehouses filled with highly explosive wildfire. The place is designed to limit the damage should a cache of wildfire combust.
* StephenieMeyer's ''Literature/TheHost''
* In the DaleBrown novel ''Fatal Terrain'', Taiwan has a secret underground air base.
* In Creator/KimNewman's short story "Literature/{{Swellhead}}", the the ghostly remains of the ElaborateUndergroundBase of a supervillain from an AlternateUniverse is beginning to seep into our world with disastrous consequences.
* The Yeerk Pool in ''Literature/{{Animorphs}}''
* The government's ''Literature/{{Daemon}}'' task force base is largely underground. The trope is subverted (in a moment that is simultaneously hilarious and horrifying) in that the Daemon's operatives [[spoiler:know exactly where the base is - in their AugmentedReality goggles there is a huge neon sign floating above it saying "Super Secret Daemon Task Force Headquarters" - and simply allow it to continue operating because it ''poses no threat to them''.]]
* The sapient rats from ''Mrs Frisby And The Rats Of NIMH'' 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.
* The Ministry of Magic in ''Literature/HarryPotter'' is completely underground that can be reached via elevator telephone booth, flushing down magic toilets (no joke), Apparation or Floo powder.
* 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.
* In StarTrekTheGenesisWave, the Lomarians (PlantAliens responsible for unleashing the titular weapon) have one of these. It's justified in that the ecological devastation on Lomar has forced their people underground.
* In the Literature/TimeScout series, half the action takes place on time terminal 86, in a winding cavernous complex in the heart of a Tibetan mountain in 1912.
* ''Literature/TheHungerGames'' gives us [[spoiler:District 13]], which is extraordinarily large.
* The Observatory in ''Literature/SeptimusHeap'' is heavily hinted at to be this.
* In the NUMASeries, Dirk Pitt has infiltrated his share of these.
* TheThrawnTrilogy has the Mount Tantiss facility on Wayland.
** To a lesser extent, the cloning facility on Dantooine in ''Literature/GalaxyOfFear''.

** ''Evil Genius''

** [[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-cannon]] and is neither mentioned by the games from the main series developers, nor does it fit with the details revealed in later games.

* The ''Black Mesa Research Facility'' in ''VideoGame/HalfLife'' is one of the biggest and most elaborate underground bases ever shown in detail. It is a repurposed top secret rocket research facility from the cold war that has been upgraded to house a massive Teleportation and Inter-Dimensional Travel research project. It has its own hydroelectric power plant, nuclear waste disposal facilities, and a dormitory complex big enough to allow at least the top researchers to have their families living with them, which also requires multiple security checks for all personnel when moving between sectors. Which is usually done by using the local monorail tram network. Some of the largest and longest levels of the game and its add-ons take place in the Fright Yard, which consists of a large number of warehouses and its own container terminal to unload the 40-feet-containers that arrive by train. The fact that outdoor environments look just awful in the old ''VideoGame/{{Quake}}'' engine may have had more than a bit to do with the base ending up mostly underground. The few outdoor levels that exist consist entirely of brown rocks and concrete walls.

* The majority of ''StillLife2'' is set in an unassuming house in the woods. The house is substantially larger than it appears due to the expanded atomic shelter underneath.

* Fanfic/DungeonKeeperAmi features this often and in diverse flavors. The Dungeons themselves, are a little more fudal, 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 hanger for the [[{{Airship}} airship fleet]], but one was actually an UnderwaterBase, and another an IslandBase...

* The Batcave from the various ''{{Batman}}'' series.

* In ''DeathNoteEquestria'', there's an old earth pony bunker underneath Ponyville town park that L uses as a base for herself and, later, the Kira investigation team.

* Fanfic/DungeonKeeperAmi features this often and in diverse flavors. The Dungeons themselves, are a little more fudal, but Ami's underground bases just keep getting more elaborate and more DungeonPunk.

* Fanfic/DungeonKeeperAmi features this often and in diverse flavors. The Dungeons them,selves, are a little more fudal, but Ami's Underground base just keeps getting more elaborate and more DungeonPunk.

** 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-Dum (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''.