History | Ancient History on Instagram: "Lake Baikal in Siberia is one of the world’s most extraordinary natural wonders because it is not only the oldest freshwater lake on Earth, estimated at more than twenty five million years old, but also the deepest, plunging to around 1,642 meters and holding more water than all the Great Lakes of North America combined. Surrounded by rugged mountains and thick taiga forests, Baikal contains an ecosystem so unique that roughly two thirds of its species ex