A blue hole is a large marine cavern or sinkhole, which is open to the surface and has developed in a bank or island composed of a carbonate bedrock (limestone...

Great Blue Hole The Great Blue Hole is a large marine sinkhole off the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll 70 km...

Dean's Blue Hole is a blue hole located in The Bahamas in a bay west of Clarence Town on Long Island and is the world's third deepest with a depth of 202...

The Blue Hole is a diving location on the southeast Sinai, a few kilometres north of Dahab, Egypt on the coast of the Red Sea. The Blue Hole is a submarine...

The Blue Hole is a fresh water pond and cenote located in Castalia, Erie County, Ohio, in the United States. From the 1920s to 1990 the Blue Hole was...

Taam Ja' blue hole Belize Taam Ja' blue hole is an underwater sinkhole located in Chetumal Bay at the southeast corner of the Yucatán Peninsula. Its name...

The Blue Hole of Santa Rosa, or simply the Blue Hole, is a circular, bell-shaped pool or small lake located along Route 66 east of Santa Rosa, New Mexico...

A blue hole is a submarine cave or sinkhole. It may also refer to: Blue Holes National Park, Andros, which claims 22 blue holes Dean's Blue Hole, Long...

Dragon Hole, also known as Yongle Blue Hole named after the third Ming emperor, was the deepest known blue hole in the world at 300.89 metres (987.2 ft)...

A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed...