I'm surprised they let them into the area. It's highly restricted, one of those places where the signs read "No Trespassing. Use of Deadly Force is Authorized."
That's where the Groom Lake AF facility is located. It's better known as Area 51, although the military never called it that. They actually declassified the area enough that you can view it from google maps now. It's an interesting way to spend a free evening.