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.

In this Thursday, May 16, 2013 file photo, Finland's Krista Siegfrids, second right, kisses a dancer as she performs her song “Marry Me” during the second semifinal of the Eurovision Song Contest at the Malmo Arena in Malmo, Sweden. That was the first girl-on-girl kiss in the history of the annual competition. Previously, organizers had sought to prevent similar embraces citing the competition's status as a family event. (Photo by Alastair Grant/AP Photo)

Yeshiva School students briefly dance on Grant Street after the menorah lighting outside of the City-County Building for the fifth night of Hanukkah, Thursday, December 26, 2019, in downtown Pittsburgh. (Photo by Alexandra Wimley/Pittsburgh Post-Gazette via AP Photo)

A sadhu (Hindu holy man) smokes marijuana using a “chillum”, a traditional clay pipe, as a holy offering during the Hindu festival “Maha Shivaratri” in Kathmandu on February 21, 2020. (Photo by Prakash Mathema/AFP Photo)

Carine Louis-Jean, 22, poses for a photograph in her destroyed house after Hurricane Matthew hit Jeremie, Haiti, October 17, 2016. “The roof of my house is completely gone and some of walls were destroyed. I have lost everything I had, but I thank God that I have a friend who is letting me stay at her house. I could say I'm lucky, because none of my family died during the hurricane, but I do not think I'm lucky”, said Louis-Jean. (Photo by Carlos Garcia Rawlins/Reuters)

Actors perform in a scene during the “Dino Safari” show in Tokyo, Japan, 25 April 2018. The Dino Safari show features dinosaurs moving in a realistic way thanks to the Dino-Tronics mechanism that enable the dinosaurs to walk, move their heads and jaws. The event will run from 26 April to 05 May 2018. (Photo by Franck Robichon/EPA/EFE)

A grey-bellied Night Monkey (Aotus Lemurinus) plays with a teddy bear at the veterinary clinic of the Cali Zoo in Cali, Colombia on January 27, 2020. They monkey is being raised by personnel of the Cali Zoo after a worker found it near the complex. Apparently it fall from a tree with his father who had health problems. (Photo by Luis Robayo/AFP Photo)