The Great Blue Hole is a large underwater sinkhole off the coast of Belize. It is a remarkable creation of nature. The Great Blue Hole is one of the world’s most recognizable natural wonder. It is believed the hole is the world’s largest sea-hole. It is about 125 meters deep and its diameter is about 300 meters wide. It has been created as a cause of sea level increase about 65,000 years ago. It was formed during several episodes of Quaternary glaciation when sea levels were much lower. The analysis of stalactites found in Great Blue Hole shows that formation has taken place 153,000, 66,000, 60,000, and 15,000 years ago. As the ocean began to rise again, the caves were flooded.