Lake Baikal ; Krugobaikalsk railroad around the Baikal lake. Lake Baikal is ( southern Siberia of Russia ) located between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, near the city of Irkutsk . It contains more water than all of the North American Great Lakes combined. Lake Baikal is the deepest lake in the world, and the largest freshwater lake in the world by volume