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.

Participants compete in a wife-carrying championship in Tapiobicske, Hungary, August 7, 2021. Some 40 Hungarian husbands, with their wives on their backs, clambered over rough terrain on Saturday in the nation's second wife-carrying contest. (Photo by Marton Monus/Reuters)

A young macaque perches on a pole, observing nearby tourists while eating some seeds in Jigokudani Yaen-koen wild macaque monkey park on February 16, 2015 in Yamanouchi, Nagano, Japan. (Photo by Manuel Romaris/Getty Images)

A rainbow appears as people enjoy a warm afternoon on a tour boat at Niagara Falls in Ontario, Canada on October 21, 2024. (Photo by Mert Alper Dervis/Anadolu via Getty Images)

A woman stands on the footbridge over the river Garry near Pitlochry, Scotland, Britain on October 10, 2018. (Photo by Russell Cheyne/Reuters)

Wrestlers compete in the 63rd Historical Cali Oil Wrestling Tournament, held on June 29, 2025, in Bursa, Turkiye. The event, which featured over 800 wrestlers and served as the final rehearsal for the 664th Historical Kirkpinar Oil Wrestling Festival, is on track to become a stage of the Oil Wrestling League, now in its third season. (Photo by Mustafa Yilmaz/Anadolu via Getty Images)

January 22, 2017; Atlanta, GA, USA; Atlanta Falcons cheerleaders take a picture in the confetti after the game against the Green Bay Packers in the 2017 NFC Championship Game at the Georgia Dome. Atlanta defeated Green Bay 44-21. (Photo by Jason Getz/USA TODAY Sports)

A boy and a woman run across a railway track as a train approaches in Chengdu, Sichuan province, China, October 8, 2015. Many residents disregard sign prohibiting this kind of illegal crossing and choose to do so to save time, local media reported. (Photo by Hao Fei/Reuters/Western China Metropolis Daily)