The deepest lake in the world is Lake Baikal, in Russia’s Siberia region.
It is 5,369 feet (1,637 m) deep, more than 1 mile, and holds one-fifth of the world’s freshwater.
Scientists think that the lake is the oldest on the planet, at more than 25 million years old.
It sits above a rift in the earth where three tectonic plates meet.
Lake Baikal is home to a large number of plants and animals, including 250 species of freshwater shrimp. One species of shrimp keeps the lake incredibly clear because it devours bacteria and algae.
In recent years, the purity of the lake has been threatened by pollution from industrial plants on its shores.