title: Blue hole
context: 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 or coral reef). Blue holes typically contain tidally influenced water of fresh, marine, or mixed chemistry. They extend below sea level for most of their depth and may provide access to submerged cave passages.[1] Well-known examples can be found in South China Sea (Dragon Hole), Belize (Great Blue Hole), the Bahamas (Dean's Blue Hole), Guam, Australia (in the Great Barrier Reef), and Egypt (in the Red Sea).
question: Where is the Blue Hole located?
answers: Well-known examples can be found in South China Sea (Dragon Hole), Belize (Great Blue Hole), the Bahamas (Dean's Blue Hole), Guam, Australia (in the Great Barrier Reef), and Egypt (in the Red Sea)