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.

Iranian worshippers chant slogans during a protest after their Friday prayer, as part of widespread anger across the Muslim world about a film ridiculing Islam's Prophet Muhammad on September 14, 2012. (Photo by Vahid Salemi/Associated Press)

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)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)

Yippie leader Jerry Rubin, barred on December 4, from House Un-American Activities subcommittee hearing, aims a toy gun in “self defense” outside the Washington hearing room on December 5, 1969. Rubin showed up in his Santa Clause suit because he believed it was typical of the committee which, he said, “is a total circus”. (Photo by Bob Daugherty/AP Photo)

A woman poses as she beside David Hammons painting on an America flag “Injustice case” at the exhibition Soul Of A Nation, exploring the art made by African American artists between 1963 and 1983, in London, Tuesday, July 11, 2017. The exhibition starts on July 12, 2017 nd ends on Oct.22, 2017. (Photo by Frank Augstein/AP Photo)

Breitling Wingwalkers aircrafts perform during an aerobatic display at an air show in Zhengzhou, Henan province, China, September 25, 201. (Photo by Reuters/Stringer)

In this March 29, 2016 photo, a man shoulders a coffin with the remains of a loved one who was slain more than two decades ago by Shining Path rebels, as he walks to the cemetery for a group burial service, in Ccano, a village in the Huanta area of Ayachcuo department, Peru. Presidential candidate Keiko Fujimori's base of support is in places like Ccano, where promises to build roads, clinics and schools recall her agronomist father’s own legacy of delivering aid to the long-overlooked countryside. (Photo by Rodrigo Abd/AP Photo)