Area51 has long been seen as the most infamous of all the "Skunk Works" bases. The facility in its legitimate life has been a hot bed of testing activity. The U2 was tested there, the SR-71, even the F117a was first flown at the dry lake bed.

But according to many researchers who have investigated Area 51, the more covert operations take place a few miles away in a small facility referred to simply as S4. S4, as its known from its map designation, was first spoken about in its covert reference by a man who claimed to have worked there as a staff scientist. His name was Robert Lazar and in 1989 he shocked the world when he claimed to not only have worked at the facility but to have been involved in a "Backwards Engineering" effort to gain a technological advantage by dismantling and rebuilding an alien spacecraft.