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 "Extraterrestrial Highway", is a popular tourist destination.