3Lake Baikal (Russia)

Lake Baikal is not only the world’s deepest lake but also one of the clearest. It reaches depths of over 5,387 feet (1,642 meters) and is known for its exceptional water purity.
Its transparency is so remarkable that in some areas, you can see up to 130 feet (40 meters) below the surface. This ancient lake is also home to unique wildlife, including the Baikal seal.