15 world's most bizarre natural phenomena

The Great Blue Hole

The Great Blue Hole is a circular submarine sinkhole off the coast of Belize, over 984 ft across and 407 ft deep. It was formed during several episodes of quaternary glaciation, also known as the current ice age.The Great Blue Hole is a part of the larger Belize Barrier Reef Reserve System, a UNESCO world heritage site. The site is very popular among scuba divers.