Area 51, also known as Groom Lake, is a secret military facility about 90 miles north of Las Vegas. It is one of the most secretive places on Earth, so secret that it isn’t on any map, and the US government denies its existence. The number refers to a 6-by-10-mile block of land, at the center of which is a large air base the government will not discuss. The site was selected in the mid-1950s for testing of the U-2 spy plane, due to its remoteness, proximity to existing facilities and presence of a dry lake bed for landings. Groom Lake is America’s traditional testing ground for “black budget” aircraft before they are publicly acknowledged. The facility and surrounding areas are also associated — with varying levels of credibility — with UFO and conspiracy stories. In 1989, Bob Lazar claimed on a Las Vegas television station that he had worked with alien spacecraft at Papoose Lake, south of Area 51. Since then, “Area 51” has become a popular symbol for the alleged U.S. Government UFO cover-up.