British Virgin Islands, British overseas territory in the eastern Caribbean Sea. It is part of an island chain collectively known as the Virgin Islands, which makes up the northeastern extremity of the Greater Antilles. Puerto Rico lies to the west. The Virgin Islands are divided administratively between the United Kingdom and the United States, the British territory lying to the north and east of the U.S. islands. The British territory consists of four larger islands (Tortola, Anegada, Virgin Gorda, and Jost Van Dyke) and 32 smaller islands and islets, of which more than 20 are uninhabited; lesser islands include Great Tobago, Salt, Peter, Cooper, Norman, Guana, Beef, Great Thatch, Little Thatch, and Marina Cay. The chief town and port is Road Town on Tortola (21 square miles [54 square km]), the largest of the islands