Lake Baikal (; , , Baygal nuur, meaning "nature lake";) is a rift lake in the south of the Russian region of Siberia, between the Irkutsk Oblast to the northwest and the Buryat Republic to the southeast.
Lake Baikal is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water, It is also among the clearest of all lakes, and thought to be the world's oldest lake at 25 million years.
Similar to Lake Tanganyika, Lake Baikal was formed as an ancient rift valley, having the typical long crescent shape with a surface area of . Bai...