A vervet monkey passes in front of a woman on the shores of lake Naivasha, Kenya January 24, 2017. (Photo by Goran Tomasevic/Reuters)

Storks casts shadows as they search for food on the dried-up Lake May in southwest Turkey on October 30, 2021. (Photo by Seyit Konyal/Solent News)

An areal view of the lake in the form of a heart in Rodgau, near Frankfurt, Germany, Friday, May 24, 2024. (Photo by Michael Probst/AP Photo)

Journalists practice social distancing outside a meeting to wrap up work on coronavirus economic aid legislation to prevent the spread of coronavirus disease (COVID-19) in Washington, U.S., March 21, 2020. (Photo by Mary F. Calvert/Reuters)

Mary Earps of England saves a penalty taken by Jennifer Hermoso of Spain (not pictured) during the FIFA Women's World Cup Australia & New Zealand 2023 Final match between Spain and England at Stadium Australia on August 20, 2023 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

American singer Rebbeca Marie Gomez, known professionally as Becky G accepts the “Latin Pop Song of the Year” award at the iHeartRadio Music Awards in Los Angeles, California, U.S. March 27, 2023. (Photo by Mario Anzuoni/Reuters)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

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.