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 sinkhole, with a maximum depth within the hole of just over 100 m (328 feet). There is a shallow opening to the sea around 6 m (20 feet) deep, known as "the saddle", and a 26 m (85 feet) long tunnel, known as "the Arch", whose ceiling is at a depth of 55 m (181 feet) and whose bottom falls away as it reaches the seaward side to about 120 m (394 feet).On the seaward side the floor drops steeply to over 1,000 metres (3,300 ft).
