Lake Baikal in southeastern Siberia, near the Mongolian border, is the deepest lake: 5,315 feet. Covering a 12,162-square-mile area (395 miles long and 4 miles wide at its widest point), the lake holds 20 percent of the world's fresh water. More than 300 rivers and streams flow into the lake, but only one, the Angara, flows out of it.
Lake Baikal is cold but teeming with aquatic life and exceptionally clear because its millions of tiny crayfish devour the plants and bacteria that could cloud the water. The lake's forested shores—and the surrounding Barguzin Mountains—are home to myriad plants and animals, many found nowhere else. The nerpa, a freshwater seal, is thought to have been breeding at Lake Baikal for 22 million years. In 1992 the Russian government designated Lake Baikal a national park.
