The Blue Hole Natural Monument comprises a gigantic underwater sinkhole surrounded by a ring of coral in the sparkling, shallow waters of the Lighthouse Reef Atoll. The Great Blue Hole, the monument’s principal attraction, is roughly 1,000 feet (300 meters) across and over 400 feet (120 meters) deep. It is the largest geological formation of its kind in the world. This collapsed cave system was likely formed above ground 10,000 years ago. You can still experience the vertical cliffs and over-hanging shelves supporting stalactites and stalagmites in the deep, blue water today, though it will take a scuba dive to experience it.
Made famous by world-renowned underwater explorer Jacques Cousteau, this remarkable site is on the bucket list of virtually every scuba diver in the world. Its vertical plunge, passing Caribbean Reef Sharks into the ancient cenote, eventually gives way to enormous stalactites and caves. If you aren’t a diver, you can still see the Great Blue Hole via aerial tours that depart daily. Even more captivating and photogenic when seen from the air, the Great Blue Hole is so large it can even be seen from space.
“Seeing the stalagmites and stalactites 140 feet down is an awesome experience. And you can’t see the bottom from there. Our dive lasted about 8 minutes at the Arch,” says TripAdvisor user @Charlieo122.
Located near the center of the Lighthouse Reef Atoll, the Blue Hole Natural Monument can be experienced by a day dive-boat trip, live-aboard dive vessel, or by air tour. Book a diving or snorkeling excursion with a sustainable, licensed tour operator or an Instagram-worthy sightseeing tour with a local airline. See our responsible visitation guidelines before visiting so you can do your part to protect the Belize Barrier Reef for future generations to enjoy.