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.

A protester reacts during a rally against the government's restrictions following the coronavirus disease (COVID-19) outbreak, in Berlin, Germany, August 29, 2020. (Photo by Christian Mang/Reuters)

A couple takes selfie pictures amid heart shaped decorations setted for Valentine's day, in Bangkok, Thailand on February 14, 2021. (Photo by Mladen Antonov/AFP Photo)

A woman carries a heart shaped balloon while sitting with her husband on a motorbike during Valentine's day, in Karachi on February 14, 2021. (Photo by Rizwan Tabassum/AFP Photo)

A man wearing a costume dives into a partly frozen lake in Shenyang, in China's northeastern Liaoning province on February 19, 2019. (Photo by AFP Photo/China Stringer Network)

A model presents a creation during the Vivienne Westwood catwalk show at London Fashion Week Women's A/W19 in London, Britain February 17, 2019. (Photo by Henry Nicholls/Reuters)

Models wear creations as part of the Moschino women's Fall-Winter 2019-2020 collection, that was presented in Milan, Italy, Thursday, February 21, 2019. (Photo by Antonio Calanni/AP Photo)

A woman counts her money as she sells flowers ahead of International Women's Day in central Kiev, Ukraine on March 7, 2019. (Photo by Gleb Garanich/Reuters)