Area 51 has to be the worst-kept secret in the aerospace industry.
It's where some of the most innovative military aircraft ever built by Lockheed Martin Corp. were flight-tested. Supposedly.
For decades, the government has refused to acknowledge the existence of the military outpost, which is about 100 miles outside of Las Vegas. Until now.
Area 51 has been recognized by the CIA, according to a newly declassified history of the U-2 spy plane. The documents were obtained under the Freedom of Information Act by Jeffrey Richelson, a National Security Archive senior fellow at George Washington University.
It's known that Area 51 was created during the Cold War so that the military could test cutting-edge projects like the U-2 without worrying about being discovered.
There have been numerous historical essays and books published about the site — even photos. But because of the new documents, the accuracy can be verified, according to Richelson.
"The newly released material provides a combination of significant new material, official confirmation of — or corrections to — what has been written," he said.
Area 51 also has been ground zero for conspiracy theorists for decades. Flying saucers. Bug-eyed aliens. Staged moon landings.
But the lengthy report contains no reference to little green men from outer space.
"There is a section on the relationship between the U-2 program being responsible for UFO sightings," Richelson said Friday. "But if people are looking for sections on dead aliens and interspecies contact, they'll be disappointed. It's just not there."