Great Blue Hole (Belize) Located in Belize's Barrier Reef Reserve System, the "Great Blue Hole" is about 60 miles away from Belize City and is believed to be the world's largest sea-hole. It's 125 meters deep and 300 meters wide. It was created as a cause of sea level increase about 65,000 years ago. Its almost perfect circular shape made it very popular among tourists who often visit this place, being the most attractive for scuba divers who are exploring its depths. Divers are also attracted with plenty of rare animal species and forms of life which can be found only in this place. Diavik Mine (Canada) The Diavik Diamond Mine is about 300 kilometers (186 miles) north of Yellowknife in Canada. It produces 8 million carats (3,500 lb) of diamonds annually. The mine is so huge and the area so remote that it even has its own airport with a runway large enough to accommodate a boeing 737. Photo Courtesy of The Diavik Diamond Mine". The Burning Gates (Turkmenistan