The Pitcairn Islands (ˈpɪtkɛərn; Pitkern: Pitkern Ailen), officially named the Pitcairn, Henderson, Ducie and Oeno Islands, form a group of four volcanic islands in the southern Pacific Ocean. The islands are a British Overseas Territory (formerly a British colony), the last remaining in the Pacific. The four islands – named Pitcairn, Henderson, Ducie, and Oeno – are spread over several hundred miles of ocean and have a total area of about 18 square miles (47 km2). Only Pitcairn, the second largest and measuring about 2 miles (3.2 km) across, is inhabited.