There's a lake that's a giant hole in the ground - Apparently.
Lake Baikal, located in southern Siberia, is the world's largest and oldest freshwater lake, holding about 20% of the world's unfrozen freshwater. It's so deep that it's often referred to as a "giant hole" - its maximum depth is approximately 1,642 meters (5,387 ft), making it the deepest lake in the world. This natural wonder is also home to over 2,500 species of plants and animals, many of which are found nowhere else on Earth.