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 woman wearing in face mask to curb the spread of COVID-19 passes street's cafe in Kyiv, Ukraine, Friday, October 22, 2021. Coronavirus infections and deaths in Ukraine have surged to all-time highs amid a laggard pace of vaccination, which is one of the lowest in Europe. (Photo by Efrem Lukatsky/AP Photo)

Models showcase collection by designer Zhang Kejia during the 2021 Kunming Fashion Week on December 15, 2021 in Kunming, Yunnan Province of China. (Photo by Li Jiaxian/China News Service via Getty Images)

Mother and son in disguise attend a Halloween celebration at Taipei Children's Amusement Park in Taipei, Taiwan, Sunday, October 29, 2023. (Photo by Chiang Ying-ying/AP Photo)

Battersea Power Station Ice Rink in London, United Kingdom on November 13, 2022. Running until 8th Jan. 2023, a large outdoor ice-rink outside the power station and next to the riverside brings in festive Christmas fun with vivid illumination. (Photo by Guy Corbishley/Alamy Live News)

Sandra, a 29-year-old orangutan at Buenos Aires' zoo, on May 20, 2015. Sandra got cleared to leave a Buenos Aires zoo that was her home for 20 years, after a court ruled she was entitled to more desirable living conditions. (Photo by Juan Mabromata/AFP Photo)

Truffle hunter Carlo Marenda pets his dog Buc as they search for white truffles through the Langhe Countryside in Roddi, near Alba, north-western Italy, on November 8, 2020. Despite new measures to stop the spread of the Covid-19, truffles hunters are allowed to search in the countryside in Italy. (Photo by Marco Bertorello/AFP Photo)

American rapper Cardi B, left, with American model Slick Woods, right, at the Moschino Miami Party, Art Basel, Miami Beach, Florida, USA on December 7, 2017. (Photo by Griffin Lipson/BFA/Rex Features/Shutterstock)