Area 51

 is a military base in Nevada. Little is known of it, apart from the fact that it exists. Area 51 is a testing ground for experimental government aircraft and extraterrestrial phenomena.

Appearances
is mentioned in the original Fallout, as a print on the crashed UFO in a special encounter. It was also supposed to appear as a location in one of the early drafts of Fallout 2, inhabited by a group of scientists. .