The United States Air Force facility commonly known as Area 51 is a remote detachment of Edwards Air Force Base, within the Nevada Test and Training Range. According to the Central Intelligence Agency (CIA), the correct names for the facility are Homey Airport (ICAO: KXTA) and Groom Lake, though the name Area 51 was used in a CIA document from the Vietnam War. Other names used for the facility include Dreamland, and nicknames Paradise Ranch, Home Base and Watertown. The special use airspace around the field is referred to as a Restricted Area 4808 North (R-4808N).

The base's current primary purpose is publicly unknown; however, based on historical evidence, it most likely supports development and testing of experimental aircraft and weapons systems (black projects). The intense secrecy surrounding the base has made it the frequent subject of conspiracy theories and a central component to unidentified flying object (UFO) folklore. Although the base has never been declared a secret base, all research and occurrings in Area 51 are Top Secret/Sensitive Compartmented Information (TS/SCI). In July 2013, following a FOIA 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, 83 miles (134 km) 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 aptly named "Extraterrestrial Highway", is a popular tourist destination.

The original rectangular base of 6 by 10 miles (9.7 by 16.1 km) is now part of the so-called "Groom box", a rectangular area measuring 23 by 25 miles (37 by 40 km), of restricted airspace. The area is connected to the internal Nevada Test Site (NTS) road network, with paved roads leading south to Mercury and west to Yucca Flat. Leading northeast from the lake, the wide and well-maintained Groom Lake Road runs through a pass in the Jumbled Hills. The road formerly led to mines in the Groom basin, but has been improved since their closure. Its winding course runs past a security checkpoint, but the restricted area around the base extends further east. After leaving the restricted area, Groom Lake Road descends eastward to the floor of the Tikaboo Valley, passing the dirt-road entrances to several small ranches, before converging with State Route 375, the "Extraterrestrial Highway", south of Rachel.

Area 51 shares a border with the Yucca Flat region of the Nevada Test Site, the location of 739 of the 928 nuclear tests conducted by the United States Department of Energy at NTS. The Yucca Mountain nuclear waste repository is 44 miles (71 km) southwest of Groom Lake.

en.wikipedia.org/wiki/Area_51