01. The Big Blue Hole, Belize
If you wish to visit it, it is located in the coral islands of Belize in the Caribbean Sea. It stands on the Lighthouse Reef about 100 miles away from its shores. It is a hole with almost perfect circle shape, 305 meters in diameter and 123 meters deep. This one stands out for its tonality that contrasts with the turquoise blue of the coral barrier that surrounds it. The origin of the great blue hole goes back to the glaciation, when the Earth was covered by glaciers and the level of the sea was lower. Then it was just a cave; as the ocean began to rise again, the caves were flooded, and the roof collapsed.