Wake Island (also known as Wake Atoll) is a coral atoll with a coastline of 12 miles (19 km) just north of the Marshall Islands. It is an unorganised, unincorporated territory of the United States, administered by the Office of Insular Affairs, U.S. Department of the Interior. About 150 people are living on its 2.85 square miles. Access to the island is restricted, and all activities on the island are managed by the United States Air Force. There is also a missile facility operated by the United States Army. The largest island, Wake Island, is the centre of activity on the atoll and is the location of Wake Island Airfield, which has a 9,800-foot (3,000 m) runway.