The US government has reportedly confirmed for the first time in publicly-released official documents that Area 51 exists.
The mysterious Air Force base located in the Nevada desert has long fascinated conspiracy theorists, because of its complex association with reports of alien landings, cover-ups and other shadowy goings-on.
But while newly declassified documents obtained by the George Washington University's National Security Archive do appear to confirm its existence, any evidence of aliens is still under lock and key (or, you know, doesn't actually exist).
Hundreds of pages have been released, however - and still make fascinating reading.
They state that the base began at the end of World War II, when President Eisenhower signed off on a project to build a new high-altitude spy plane. The craft - which became the U-2 - needed a new and secret place from where it could be securely flown. Hence Area 51.
The documents explain that the area was first spotted from the air:
On 12 April 1955 [CIA officer] Richard Bissell and Col. Osmund Ritland (the senior Air Force officer on the project staff) flew over Nevada with [Lockheed's] Kelly Johnson in a small Beechcraft plane piloted by Lockheed's chief test pilot, Tony LeVier. They spotted what appeared to be an airstrip by a salt flat known as Groom Lake, near the northeast corner of the Atomic Energy Commission's (AEC) Nevada Proving Ground.
After debating about landing on the old airstrip, LeVier set the plane down on the lakebed, and all four walked over to examine the strip. The facility had been used during World War II as an aerial gunnery range for Army Air Corps pilots. From the air the strip appeared to be paved, but on closer inspection it turned out to have originally been fashioned from compacted earth that had turned into ankle-deep dust after more than a decade of disuse.
Eventually it was agreed to turn the wasteland into a full-scale base on the edge of Groom Lake.
"President Eisenhower also approved the addition of this strip of wasteland, known by its map designation as Area 51, to the Nevada Test Site. The outlines of Area 51 are shown on current unclassified maps as a small rectangular area adjoining the northeast corner of the much larger Nevada Test Site."
The Atlantic has gone through some of the 407-page document to find some interesting details. They include details about British participation in the U-2 and Area 51 project, and details of flights made over China in the 1960s.
Reportedly, Eisenhower believed British participation was useful "as a way to confuse the Soviets as to sponsorship of particular overflights" and a way to spread the risk of failure.
The documents show that four RAF officers joined the project at Area 51 in 1958. One British pilot - Squadron Leader Christopher H. Walker - died in a training accident while flying a U-2 out of a base in Texas in July of that year.
"By 1957 cooperation between the United Kingdom and the United States had expanded to include frequent consultation between the requirements and photointerpretation organizations of both countries," the documents say.
They add that in Britain the cover-story for RAF participation in the U-2 project was that pilots were being trained to fly high-altitude weather sampling missions. A U-2 was actually sent to Watton RAF Base in 1959 and used to fly weather missions for two days to support the story.