The "Great Blue Hole" couldn't be a more fitting name for the underwater sinkhole off the coast of Belize. The circular site, which can be viewed from space, has become a bucket-list destination for travellers and scuba divers alike. At 300 metres wide and 125 metres deep, the dark blue hole is located at the centre of an atoll called Lighthouse Reef. Though the sinkhole appears to continue down an infinite depth, an island of coral that outlines the circle rests in much shallower turquoise Caribbean waters. Parts of the ring are even exposed during low tides, showing the contrast in water levels.
The massive hole wasn't always submerged underwater. During the Earth's glacial period when the sea level was much lower, the Great Blue Hole originally formed as a limestone cave. But as the ocean began to rise, the cave flooded and eventually collapsed, becoming the popular dive site it is today. The former cave's calcium salt deposits, which look like yellow icicles, are still preserved and can be seen on one's swim.
It wasn't until 1971 when Jacques Cousteau explored the site and confirmed its origins that the site became world-famous. Supposedly, the deeper you dive, the clearer the water becomes and the more complex geological formations appear. It's also believed that the Great Blue Hole is the largest of its kind.
See the breathtaking photos ahead!