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).
The Snow Hole
The Snow Hole is located in the Taconic Mountains, New York, USA along the ridge line between Bald Mountain and the White Rock (Taconic Mountains). It is a crevasse in which snow can be found well into the summer. The Snow Hole can be accessed by hiking the Taconic Crest Trail about 2.75 miles north from the Petersburgh Pass parking area just off of Route 2. The Snow Hole is located at . Finding the location of the Snow Hole can be confusing, as several maps (including Google maps and USGS Berlin quadrangle, 1:25,000 scale - 1988) mark the location of the Snow Hole "summit" at . However, that is a separate mountain summit and not the actual Snow Hole. The posted hiking map at the kiosk to the Taconic Crest Trail at Petersburgh Pass has the location correctly identified. Typically the crevasse has snow at the bottom of it year round.