The Great Blue Hole in Belize

The Great Blue Hole is a large underwater sinkhole off the coast of Belize, in Central America. It lies near the center of Lighthouse Reef, a small atoll 100 km (62 miles) from the mainland and Belize City. The hole is circular in shape, over 300 metres (984 ft) across and 125 metres (410 ft) deep. It was formed as a limestone cave system during the last glacial period when sea levels were much lower. As the ocean began to rise again, the caves flooded, and the roof collapsed. Believed to be the world’s largest feature of its kind, the Great Blue Hole is part of the larger Belize Barrier Reef Reserve System, a World Heritage site of the United Nations Educational, Scientific and Cultural Organization (UNESCO).

This site was made famous by Jacques Yves Cousteau in 1971, who declared it one of the top ten scuba diving sites in the world. This is a popular spot amongst recreational scuba divers, who are lured by the opportunity to dive in crystal clear water and meet several species of fish, including giant groupers, nurse sharks and several other types of reef sharks.

Source: Wikipedia