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.

Palmeiras' Gustavo Scarpa celebrates with the trophy after winning the Paulista Championship in Sao Paulo, Brazil, April 3, 2022. (Photo by Amanda Perobelli/Reuters)

Judges watch athletes during the women's individual compact NH 5km competition at the Nordic Combined World Cup in Ramsau, Austria, Saturday, December 16, 2023. (Photo by Matthias Schrader/AP Photo)

A tourist splashes water on the frozen Songhua River on December 18, 2023 in Harbin, Heilongjiang Province of China. The water immediately freezes into ice in the frigid air. (Photo by VCG/VCG via Getty Images)

A man applies coats of glass powder to kite strings ahead of the Hindu festival “Uttarayan” in Ahmedabad on December 21, 2023. (Photo by Sam Panthaky/AFP Photo)

Dressed up participants run at the “Course de la Marmite” during the 46th Escalade Race (Course de l'Escalade) in Geneva, Switzerland, 07 December 2024. (Photo by Martial Trezzini/EPA/EFE)

A member of the Brotherhood of the Diablos Danzantes de Chuao (Dancing Devils of Chuao) arranges his mask during the Corpus Christi festival in the town of Chuao, Aragua state, Venezuela on June 18, 2025. (Photo by Maxwell Briceno/Reuters)

Darren Julien poses with two of Princess Diana's dresses which will be auctioned through WE tv & Wedding Central at Julien's Auctions in Beverly Hills on May 7th in celebration of the Royal Wedding, with a portion of the proceeds going to charity are shown at Times Square on April 20, 2011 in New York City. (Photo by Slaven Vlasic/Getty Images)