Dulce Base

The alleged seven-level facility under a New Mexico mesa, with a floor called Nightmare Hall.

The story reaches print through Paul Bennewitz, a physicist watching lights over the Manzano nuclear storage site — who was, documents later showed, deliberately fed disinformation by Air Force intelligence until he broke. Out of that poisoned well came the seven levels, the vats, Nightmare Hall, and a 1979 'firefight' with sixty casualties. No entrance has ever been found. The disinformation operation, however, was real — which leaves the question of what it was protecting.