Andros Island is the largest island of the Bahamas and the fifth largest island in the West Indies at roughly 6,000 km² (2,300 sq mi) in area and 167 km (104 mi) long and 64 km (40 mi) wide at its widest point. It is actually composed of three major islands: North Andros, Mangrove Cay, and South Andros. The island has the world's third largest barrier reef, which is over 225 km (140 mi) long. It is affectionately known by Bahamians as the "Big Yard".