Andros Island is the largest island of the Bahamas and the fifth largest island in the West Indies at roughly 2300 square miles (6,000 km²) in area and 104 miles (167 km) long and 40 miles (64 km) 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 140 miles long. It is affectionately known by Bahamians as the "Big Yard".