Dean's Blue Hole

Dean's Blue Hole is the world's deepest known saltwater blue hole, plunging 202 metres through the limestone shelf in a sheltered bay on Long Island's west coast. Scuba divers descend through a dramatic circular opening roughly 25 metres wide at the surface that widens to an enormous cavern at depth, the walls fading from bright turquoise to indigo to absolute black as sunlight gives way to darkness. Famous globally as the premier freediving destination — the site of multiple world records — it draws technical divers and open-water divers alike to its eerie, cathedral-like interior.