In which country is the highly classified research base, Area 51 located?

Area 51 is the common name of a highly classified United States Air Force (USAF) facility located within the Nevada Test and Training Range.

Details of the facility's operations are not made public, but the USAF says that it is an open training range, and it is commonly thought to support the development and testing of experimental aircraft and weapons systems. The USAF acquired the site in 1955, primarily for flight testing the Lockheed U-2 aircraft.

The intense secrecy surrounding the base has made it the frequent subject of conspiracy theories and a central component of unidentified flying object (UFO) folklore. The base has never been declared a secret base, but all research and occurrences in Area 51 are Top Secret/Sensitive Compartmented Information (TS/SCI).

Area 51 is located in the southern portion of Nevada, 83 miles (134 km) north-northwest of Las Vegas. The surrounding area is a popular tourist destination, including the small town of Rachel on the "Extraterrestrial Highway".