What is the largest freshwater lake by volume in the world, containing roughly 20% of the world's unfrozen surface fresh water?

Lake Baikal is a rift lake in Russia, located in southern Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast.

Lake Baikal is the largest freshwater lake by volume in the world, containing roughly 20% of the world's unfrozen surface fresh water. With a maximum depth of 1,642 m (5,387 ft), Baikal is the world's deepest lake. It is considered among the world's clearest lakes and is considered the world's oldest lake — at 25 million years. It is the seventh-largest lake in the world by surface area. With 23,615.39 km3 (5,700 cu mi) of fresh water, it contains more water than all the North American Great Lakes combined.