For decades, the top secret US military base Area 51 has obsessed the world's UFO-logists and conspiracy theorists.
Scores of people claim to have spotted strange craft hovering over the Nevada desert base and some believing that a flying saucer and its alien occupants were taken there after crash landing at Roswell, New Mexico, in 1947.
Now, for the first time, the US government has acknowledged the existence of Area 51 in a recently declassified internal history of the U-2 spy plane programme, but to the likely disappointment of legions of UFO aficionados, makes no mention of captured spacecraft or visitors from outer space.
The information was acquired after a public records request by the National Security Archive at George Washington University in Washington DC.
Many of the documents were made public in 1998, but were heavily redacted.
The report reveals that the site by Groom Lake was acquired by the government in 1955, with the purchase order personally signed by president Dwight D Eisenhower.
CIA and US Air Force bosses proposed the location for its remoteness and proximity to a nuclear testing facility after scouting it from the air.
It was originally named Paradise Ranch, later shortened to The Ranch, to make the arid site more appealing to managers and workers on top secret aircraft programmes.
Pilots were flown in to start testing prototypes of the U2, and the authors of the history write that shortly after there was "a tremendous increase in reports of UFOs".
"At this time, no one believed manned flight was possible above 60,000 feet, so no one expected to see an object so high in the sky," note authors Gregory Pedlow and Donald Welzenbach.
The U-2 was absolutely top secret," Chris Pocock, a British defence journalist and author of histories of the programme, told the BBC.
"They had to hide everything about it."
Other top-secret aircraft tested there included the supersonic reconnaissance A-12 aircraft, code-named OXCART, and the F-117 stealth ground-attack jet, archive senior fellow Jeffrey Richelson, who requested the redactions to be lifted, told Reuters.
"It's the first time that there must have been a senior-level decision to acknowledge the term 'Area 51' and its specific location," said Richelson.
"What readers of the CIA study will find is that CIA tests its U-2 and A-12 reconnaissance aircraft at the site in Nevada sometimes referred to as 'Area 51,'" CIA spokesman Edward Price said. "What readers won't find are any references to aliens or other conspiracy theories best left to the realm of science fiction."