Lesser Known Wonders Of The World: Great Blue Hole

The Great Blue Hole is a large underwater sinkhole off the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll 70 kilometres (43 miles) from the mainland and Belize City. The hole is circular in shape, over 300 metres (984 ft) across and 124 metres (407 ft) deep. It was formed during several episodes of Quaternary glaciation when sea levels were much lower - the analysis of stalactites found in Great Blue Hole shows that formation has taken place 153,000; 66,000; 60,000; and 15,000 years ago. As the ocean began to rise again, the caves were flooded. The Great Blue Hole is a part of the larger Belize Barrier Reef Reserve System, a World Heritage Site of the United Nations Educational, Scientific and Cultural Organization

 Lighthouse Reef as seen from space. The Great Blue Hole is near the center of the photograph.