The deepest freshwater lake is Lake Baikal in Russia. Due to the enormity of the lake, there are many worms and sponges located there. As a matter of fact, a couple of hundred different kinds of worms found in or around this lake. Also, there are over 18 types of sponges. During the Han-Xiongnu War, both sides fought at the Lake Baikal. During the Han dynasty, the soldiers fought next to this large lake where they noted its size.
Instead of calling it Lake Baikal, they named it the North Sea. A tribe which lived close to the sea named it a title that means “much water” due to the depth of this lake. Then they called it “natural lake.” Several other names were given to this lake over time.