The Great Blue Hole is a large marine sinkhole located off the coast of Belize. It is part of the Belize Barrier Reef, a UNESCO World Heritage Site, and measures approximately 300 meters (1,000 feet) across and 125 meters (410 feet) deep. The hole is known for its stunning blue color and unique underwater formations, attracting divers and marine enthusiasts from around the world. This natural wonder was formed during the last ice age when sea levels were much lower. As the climate warmed, rising sea levels flooded the limestone cave system, creating the sinkhole we see today. The Great Blue Hole is home to diverse marine life, including various species of fish, coral, and even sharks.