So just how did The Great Blue Hole happen? Turns out that cavern was formed on land during the last ice age, tens of thousands of years ago. It started as a limestone cave that sunk when the ground collapsed and a giant circular hole formed –– which was then filled by the rising Caribbean Sea.
Made famous by renowned marine biologist, Jacques Cousteau, in the 1970s, the Great Blue Hole is a popular destination for divers the world over. Located in the middle of an atoll (a ring-shaped reef, island, or chain of islands made of coral) off the coast of Belize in Central America, the Great Blue Hole is a protected World Heritage site.
With the stunning contrast of dark against light, shallow against deep, nature has once again provided a masterpiece of nature, a true gem in the middle of the sea.