The U.S. military maintains control over nearly one third of the island's total land area. Significant military zones are located both in northern and southern half of the island, but the proportion of military lands to the total is higher in the north. The northernmost part of the island is designated as Anderson Air Force Base. Most of the Philippine Sea coast of northern Guam falls within U.S. Naval Computer and Telecommunications Station. There are also several smaller areas and annexes in Barrigada, Mangilao, and Tamuning.