Area 51 request filed in 2005, the CIA publicly acknowledged the existence of the base for the first time, declassifying documents detailing the history and purpose of Area 51. Area 51 is located in the southern portion of Nevada in the western United States, north-northwest of Las Vegas. Situated at its center, on the southern shore of Groom Lake, is a large military airfield. The site was acquired by the United States Air Force in 1955, primarily for the flight testing of the Lockheed U-2 aircraft. The area around Area 51, including the small town of Rachel on the "Extraterrestrial Highway", is
Area 51 show what appears to be F-16 Fighting Falcon aircraft stationed on the base. Its secretive nature and undoubted connection to classified aircraft research, together with reports of unusual phenomena, have led Area 51 to become a focus of modern UFO and other conspiracy theories. Some of the activities mentioned in such theories at Area 51 include: Many of the hypotheses concern underground facilities at Groom or at Papoose Lake (also known as "S-4 location"), south, and include claims of a transcontinental underground railroad system, a disappearing airstrip (nicknamed the "Cheshire Airstrip", after Lewis Carroll's Cheshire cat) which briefly appears when