A mysterious underwater cave
uring the Ice Age, between 15 000 and 150 000 years ago, a giant sinkhole formed off the coast of Belize in central America. Called the Great Blue Hole, this massive, a ring-shaped coral reef about 80km from the Belize coastline. It stretches 300m across and is estimated to be 125m deep. While most sinkholes form on land surfaces, blue holes like the one in Belize form within the ocean and create deep marine caverns. The Great Blue Hole is the largest natural formation of its kind in the world.
