Great Blue Hole
The Great Blue Hole is a giant marine sinkhole off the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll from the mainland and Belize City. The hole is circular in shape, across and deep. It was formed during several episodes of quaternary glaciation when sea levels were much lower. Analysis of stalactites found in the Great Blue Hole shows that formation took place 153,000; 66,000; 60,000; and 15,000 years ago. As the ocean began to rise again, the cave was flooded. The Great Blue Hole is a part of the larger Belize Barrier Reef Reserve System, a World Heritage Site of the United Nations Educational, Scientific and Cultural Organization (UNESCO).
Blue Hole (New Jersey)
After people became afraid of it, the Blue Hole was largely abandoned. A possibility is that farmers and families in the area warned children against going to the Blue Hole because the Jersey Devil lived there and it would hurt or steal them. Locals still go to the area and use it as a party spot. There are many other 'blue holes' in the immediate vicinity, as well as quicksand and other seasonal ponds and lakes that form from springs seeping from high water table levels. The Blue Hole is not to be confused with the numerous former quarries in the area, which appear much larger and have a vibrant sky blue color.