Area 51 is a remote tract of land in the southwestern portion of Lincoln County in southern Nevada.  Situated at its center, on the southern shore of a dry lakebed (salt lake), is a large military airfield, one of the most secretive places in the world. The base's primary purpose is to support development and testing of experimental aircraft and weapons systems.

The base lies within the United States Air Force's vast Nevada Test and Training Range. Although the facilities at the range are managed by the 99th Air Base Wing at Nellis Air Force Base, the Groom facility appears to be run as an adjunct of the Air Force Flight Test Center at Edwards Air Force Base in the Mojave Desert, around 160 miles from Groom, and as such the base is known as Air Force Flight Test Center.

The intense secrecy surrounding the base, the very existence of which the US Government barely acknowledges, has led it to become the frequent subject of conspiracy theories and UFO folklore.

Rachel is an unincorporated portion of Lincoln County, Nevada. As the closest habitation to the Nellis Air Force Range and Area 51, Rachel enjoys a modest celebrity, particularly among aviation enthusiasts and UFO hunters.

The town lies approximately three hours drive north of Las Vegas along Nevada Highway 375 (the "Extraterrestrial Highway"). The tiny town receives a modest number of visitors interested in the U.S. government's secret doings to the west, to whom a small tourist shop and an alien-themed bar cater, the Little A'Le'Inn.