In this aerial view fishing boats are seen on the shore of the Lake Malawi at the Senga village on May 20, 2019 in Senga, Malawi. Hundreds of local traders gather each morning and afternoon at Senga, but fish populations are falling in Lake Malawi, Africa's third largest body of freshwater. (Photo by Gianluigi Guercia/AFP Photo)

A young Chinese girl kicks during a kung-fu class at Ritan Park on June 11, 2016 in Beijing, China. Ritan, meaning “sun altar”, is among the oldest parks in Beijing, built in the early 1500s during the Ming dynasty for the emperor to make sacrifices to the sun. (Photo by Kevin Frayer/Getty Images)

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)

An aerial view of Lake Salt as teams conduct salt extraction works at lake which is a significant portion of Turkiye's salt need is met in Ankara, Turkiye on August 11, 2022. Salt extraction works lasts for about 3 months and continues with the recession of the waters in Lake Salt. The salt extracted from the lake, where salt is produced with a purity of 99 percent, is sent to more than 60 countries. (Photo by Emin Sansar/Anadolu Agency via Getty Images)

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 cyclist rides the path around Lake Harriet on Memorial Day in Minneapolis on Monday, May 25, 2020. The area around the Lake Harriet Bandshell was busy but not crowded on Memorial Day evening. (Photo by Jeff Wheeler/Star Tribune via AP Photo)

Migingo is a tiny 2,000-square-metre (0.49-acre; 0.20-hectare) island, about half the size of a football pitch, in Lake Victoria. Migingo is a tiny rock island, less than half-an-acre or about half the size of a football field, located in Lake Victoria, the largest lake in Africa and the largest tropical lake in the world. Although tiny in size, the island is home to 131 people (according to 2009 census) living in crammed huts made of corrugated sheets and wood. Despite shabby living conditions, Migingo Island boasts of five bars, a beauty salon, a pharmacy as well as several hotels and numerous brothels.