Yap, state of the Federated States of Micronesia, part of the Caroline Islands in the western Pacific Ocean. The total land area of Yap state is 119 sq km (46 sq mi).
The state consists of outlying coral atolls and Yap proper, a cluster of four main islands within a lagoon formed by an outer band of islets. The main islands of Yap proper were formed by an uplifting of the Asian continental shelf. Their interiors consist of rolling hills rather than mountains, which are typical of other volcanic islands. Agriculture and fishing are the chief economic activities, and copra (dried coconut meat) is the chief export.
The traditional form of currency consisted of large stone disks with holes in the center, but United States currency is now commonly used. There are many relics of an early civilization on the atoll. The main settlement is Colonia.
The first Europeans to sight Yap were the Spanish, in 1791. Yap was a possession of Spain until 1899, when it was sold to Germany. Japan occupied the islands in 1914, upon the outbreak of World War I, and in 1919 they were mandated to Japan by the League of Nations. Yap was utilized by Japan as a naval and air base during World War II; following its defeat in 1945, Japan surrendered Yap to U.S. troops. In 1947 Yap, as a part of the Caroline Islands, was placed under the Trust Territory of the Pacific Islands and assigned to the United States by the United Nations Security Council. In 1979 it became part of the newly formed Federated States of Micronesia.