Blue Hole:
The Blue Hole is a submarine sinkhole, around 94m (300 feet) deep. There is a shallow opening around 6m deep, known as "The Saddle", opening out to the sea, and a 26m long tunne;, known as "The Arch", whose top is at a depth of 56m (184 feet). The hole and the surrounding area have an abundance of coral and reef fish.