The Virgin Islands are the western island group of the Leeward Islands, which are the northern part of the Lesser Antilles, and form the border between the Caribbean Sea and the Atlantic Ocean. Politically, the eastern islands form the British Virgin Islands and the western ones form the Virgin Islands of the United States. The British Virgin Islands is an overseas territory of the United Kingdom comprising Tortola, Virgin Gorda, Jost Van Dyke and Anegada. The U.S. Virgin Islands is one of five inhabited insular areas of the United States, along with American Samoa, Guam, Northern Mariana Islands, and Puerto Rico. The territory comprises St. Croix, St. John, St. Thomas and Water Island. The Virgin Passage separates the U.S. Virgin Islands from the Spanish Virgin Islands of Vieques and Culebra, which are part of Puerto Rico. The United States dollar is the official currency on both the British and U.S. Virgin Islands as well as the Spanish/Puerto Rican Virgin Islands.