THE BELIZE BLUE HOLE A contender of the eight wonders of the world Located off the coast of Belize within the Lighthouse Reef Atoll, the Belize Blue Hole is a perfectly circular underwater sinkhole. What was previously a limestone cave system, is now one of the most unique natural creations known as the Belize Blue Hole. As sea levels rose during the last Ice Age, the cave flooded and its roof collapsed into this sinkhole resulting in a marine wonder known for its sparkling blue waters, wealth of coral formations, sharks and fish, and deep caves filled with stalactite