Oldest lake
- Who
- Lake Baikal
- What
- 20–25 million year(s)
- Where
- Russian Federation (Siberia)
- When
- 01 January 0001
Lake Baikal, Siberia, Russia, is between 20 and 25 million years old, and was formed as a result of a tectonic rift in the Earth's crust. The rift is very much active and is causing Baikal to continue to widen at an approximate rate of 2 cm (0.7 in) per year. It holds more water than all of North America's Great Lakes combined and is host to a wealth of biodiversity, including the world's only freshwater seal.