Anguilla Anguilla ( ) is a British overseas territory in the Caribbean, one of the most northerly of the Leeward Islands in the Lesser Antilles. It consists of the main island of Anguilla itself, approximately long by wide at its widest point, together with a number of much smaller islands and cays with no permanent population. The island's capital is The Valley. The total land area of the territory is , with a population of approximately 13,500 (2006 estimate).