Dean's Blue Hole is a natural underwater sinkhole located near Long Island in the Bahamas. It is renowned for being the deepest blue hole in the world, reaching a depth of approximately 202 meters (663 feet). The hole is surrounded by a sandy beach and shallow waters, making it a popular spot for divers and snorkelers. The blue hole is named after Dean's Blue Hole beach, which is situated nearby. Its striking blue color is due to the depth and clarity of the water, which allows sunlight to penetrate deeply. This unique geological formation attracts both adventure seekers and researchers interested in marine life and underwater ecosystems.