The lake Baikal is situated in south-central Siberia, Russia. It is recognized as the world's deepest lake. It is approximately 1,642 meters (5,387 feet) deep. It is believed to be 25–30 million years old. It is also recognized as the largest lake in terms of volume, holding 20–23% of the world's unfrozen surface freshwater, more than all of the Great Lakes combined in North America.