What is the deepest known freshwater lake in the world?

Lake Baikal is the deepest known freshwater lake in the world.

Located in southern Siberia, Russia, Baikal reaches a maximum depth of about 1,642 metres. It is also the world’s oldest existing freshwater lake, with an estimated age of roughly 25 million years, and contains about 20 percent of the planet’s unfrozen surface freshwater.

Baikal formed in an active continental rift zone, where the Earth’s crust is pulling apart. Its great depth and long geological history have allowed many distinctive species to evolve. The lake’s best-known endemic animal is the Baikal seal, the only seal species that lives exclusively in freshwater.

Lake Tanganyika is the second-deepest lake and also lies in a tectonic rift. Lake Superior is the largest freshwater lake by surface area, but it is far shallower than Baikal. These different records explain why “largest” and “deepest” produce different answers.