Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

Revellers take part in New Year celebrations in Coin, near Malaga, southern Spain, January 1, 2016. (Photo by Jon Nazca/Reuters)

A woman arrives at the Shinto Meiji Shrine to pray on the first day of the new year in Tokyo, Japan, January 1, 2016. (Photo by Thomas Peter/Reuters)

A Virgin Atlantic passenger plane flies in the sky with the moon seen in the background, in London, Britain January 19, 2016. (Photo by Toby Melville/Reuters)

A participant runs through foam during the Love Foam Run race in Hsinchu, Taiwan May 29, 2016. (Photo by Tyrone Siu/Reuters)

Ecuadorian luthier Ivan Ibujes plays a guitar after repairing it at his shop in Quito, June 17, 2016. (Photo by Guillermo Granja/Reuters)

Sniper rifles sit on display for sale at the “Ready Gunner” gun store in Provo, Utah, U.S., June 21, 2016. (Photo by George Frey/Reuters)