Area 51

Truth be told, most of what goes on at the Groom Lake Airforce Base is simply the testing of experimental American military aircraft. But Groom Lake was chosen as the location for those tests because it was already set up to be a highly secretive base.

And that's because, decades ago, Majestic-12 picked the remote site to be their warehouse and repository for all things weird and confidential they recovered.

See, Majestic-12 is the American military's occult intelligence division. It's basically their job to assess and contain paranormal, supernatural and extraterrestrial threats. They were set up via a confidential executive order by President Harry Truman, following the Roswell crash, to investigate this new, alien threat to America. Since then, they've expanded their mandate beyond the extraterrestrial to anything beyond conventional, including vampires, werewolves, demons, fairies, bogeymen, genies and eldritch abominations from between the stars.

While formally headquartered in Arlington, Virginia, Majestic-12's true base of operations is Area 51. That's where they conduct most of their R&D efforts, that's where most of their active forces are garrisoned, and that's where they warehouse all those artifacts they've gathered over the years, be they Atlantean scrolls, Martian currency, hell-forged swords, or the wreckage of alien craft shot down over rural Iowa.

And the whole base is built on top of a ley line nexus, which Majestic-12 uses to ward the site, but also warp the space beneath. See, the surface complex represents maybe a tenth of the total size of the facility, the rest of it existing within a spatial bubble created beneath the site. After all, hiding most of your facility on the Astral plane is a great way to ensure your rivals never get a full grasp on the size of your operations.

Of course, most other nations have their own variations on Majestic-12, with their own facilities. And then there are the conspiracies such as the Illuminati, the Templars, the Assassins and the Green Dragon. But none of their sites have ever reached the infamy of Area 51.