Area 51 is located in the southern portion of Nevada in the western United States, which is 83 miles (133 km) away from north-northwest of Las Vegas. Area 51 is a nickname for a large military airfield. The primary purpose of this area is to support development and testing of experimental aircraft and weapons systems, but the area became a subject of conspiracy theories and a central component to unidentified flying object (UFO) myths. There is also a sign stated that if people try to enter the Area 51 zone, deadly force can be used on them.