Fort Detrick has vast underground caverns or caves.
Bio warfare work is the name of the game there.
I know... USAMRID is located there... Whiteman AFB had (I believe that they've been deactivated - I know the Titan IIs were, but I could be wrong) quite a bunch of ICBM silos, as well as nuclear armed SAC bombers.
Against the Soviets, it was protection, but still just knowing how close I was to all those nuclear warheads was a bit daunting. And being escorted and closely watched by armed guards past all of those "Use of deadly force authorized" signs brought it home.