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).
Mel's Hole
Waters made guest appearances on Bell's show in 1997, 2000, and 2002. Rebroadcasts of those appearances have helped create what's been described as a "modern, rural myth". The exact location of the hole was unspecified, yet several people claimed to have seen it, such as Gerald R. Osborne, who used the ceremonial name Red Elk, who described himself as an "intertribal medicine man...half-breed Native American / white", and who told reporters in 2012 he visited the hole many times since 1961 and claimed the US government maintained a top secret base there where "alien activity" occurs. But in 2002, Osborne was unable to find the hole on an expedition of 30 people he was leading.