Palmyra Atoll, coral atoll, unincorporated territory of the United States, in the Northern Line Islands in the west-central Pacific Ocean, about 1,000 miles (1,600 km) southwest of Honolulu. It comprises some 50 islets with a combined area of 4 square miles (10 square km) and an average elevation of only 6 feet (2 metres) above sea level. The atoll was sighted in 1798 by an American ship under the command of Capt. Edmund Fanning, but the ship did not land. In 1802 the American ship Palmyra made landfall. The atoll was annexed by the Kingdom of Hawaii in 1862 and by Britain in 1889. In 1898 the United States annexed Palmyra as part of the Hawaiian Islands territory. During World War II the atoll’s central lagoon and joined islets were used as airstrips. When Hawaii became a state in 1959, Palmyra was not included. The atoll, once a producer of copra, is a nearly unspoiled tropical wilderness that is home to many species of coral, marine animals, and seabirds. It was declared a U.S. National Wildlife Refuge in 2001 after its purchase by a private conservation group. In 2009 it was designated part of the Pacific Remote Islands Marine National Monument. There are no permanent inhabitants.