It’s called the Great Blue Hole and it lies off the coast of Belize. The hole is shaped as a circle, measures over 984 feet across and is 407 feet deep.
According to stalactites analysis, the Great Blue Hole was formed on dry land, during a past ice age when sea levels were significantly lower than today. The circular pit submerged as the sea levels rose in the Caribbean.
The Great Blue Hole of Belize is a popular spot for recreational scuba divers. Different species of fish made the hole their home. This includes the Midnight Parrotfish, Caribbean reef shark and other juvenile fish species. Sharks, like the bull shark and hammerheads, have also been spotted in the area. However, they are not seen as often
One of the main attractions of the sea hole is the crystal-clear water. When you dive, you can see the water shimmer when you’re fifty below the surface. It’s because you can spot halocline—the invisible line that divides the salty top of the hole from its fresh water depths.
Glyn Collinson, a NASA scientist who recently dived the Great Blue Hole described it thus:
“It was the deepest, deep blue hole imaginable; A chasm that fell away deep into the deep, dark blue. It had been forged out of solid rock as caverns, hundreds of thousands of years ago during the last ice age. For eons, water filtered through the rock and into these great stone cathedrals, breeding multicolored stalactites and stalagmites. Then, one by one they collapsed in on each other, creating a chasm four hundred feet deep. As Earth’s swollen polar ice-caps receded, the warm Caribbean ocean swept in to fill the chasm with boiling white hands, the last rays of sunlight struck the chasm’s floor. Then, as the limestone broke down, it began to rain tiny fragments of rock, which slowly began to fill the great Blue Hole.”
In 2012, Discovery Channel ranked the Great Blue Hole as number one on its list of “The 10 Most Amazing Places on Earth.”