Ascension is a British island in the South Atlantic Ocean.  Its area is 34 square miles (88 square km), and it is a dependency of the colony of St. Helena, 700 miles (1,100 km) to the southeast. Except on the heights of Green Mountain (2,817 feet [859 m]), where fruit, vegetables, and livestock are raised, the island is mostly a desolate desert of extinct volcanic craters and extensive and permeable lava fields, which exclude surface streams. Nineteenth-century catchment basins on Green Mountain yield some fresh water, but the bulk of the supply is produced in desalinisation plants. Unprotected by coral reefs, the sandy beaches are vulnerable to heavy oceanic swells but are critical nesting sites for the globally endangered green sea turtles, which come ashore to lay eggs between January and April. Sooty terns also breed in abundance, but other birds have suffered major depredations by feral cats.

The Portuguese navigator Joćo da Nova Castella discovered the island in 1501 (on Ascension Day), but it remained uninhabited until 1815, when British marines were stationed there to discourage Napoleon's escape from St. Helena. An "administrator," under the governor of St. Helena, has represented the British crown since 1922, but the economy depends on communications facilities operated by Cable and Wireless PLC, the British Broadcasting Corporation, the U.S. National Aeronautics and Space Administration, the U.S. Air Force, the Royal Air Force, and British and American intelligence organizations. About half the population are St. Helenian contract labourers, about 200 are Americans, and the remainder are metropolitan British. There are no permanent residents on the island.

Wide-awake Airfield was built by American engineers during World War II.  It was critical to British success during the Falkland Islands war of 1982, when a big tent camp of British marines and soldiers sprang up overnight. Ascension is a refulling point for Royal Air Force flights between the United Kingdom and the Falklands.  U.S. flights travel from Patrick Air Force Base, Florida, via the Caribbean island of Antigua.  Access to Ascension is limited, although private yachts may remain for three days, at the discretion of the administrator.