<P> The Great Blue Hole is a giant marine sinkhole off the coast of Belize . It lies near the center of Lighthouse Reef , a small atoll 70 km ( 43 mi ) from the mainland and Belize City . The hole is circular in shape , 318 m ( 1,043 ft ) across and 124 m ( 407 ft ) deep . It was formed during several episodes of quaternary glaciation when sea levels were much lower . Analysis of stalactites found in the Great Blue Hole shows that formation took place 153,000 ; 66,000 ; 60,000 ; and 15,000 years ago . As the ocean began to rise again , the cave was 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 ( UNESCO ) . </P>
<P> The Great Blue Hole is a giant marine sinkhole off the coast of Belize . It lies near the center of Lighthouse Reef , a small atoll 70 km ( 43 mi ) from the mainland and Belize City . The hole is circular in shape , 318 m ( 1,043 ft ) across and 124 m ( 407 ft ) deep . It was formed during several episodes of quaternary glaciation when sea levels were much lower . Analysis of stalactites found in the Great Blue Hole shows that formation took place 153,000 ; 66,000 ; 60,000 ; and 15,000 years ago . As the ocean began to rise again , the cave was 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 ( UNESCO ) . </P>
where is the blue hole located in belize
where is the blue hole located in belize
near the center of Lighthouse Reef , a small atoll 70 km ( 43 mi ) from the mainland and Belize City
near the center of Lighthouse Reef , a small atoll 70 km ( 43 mi ) from the mainland and Belize City