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 five meters high sculpture “Pentateuque” created by Contemporary French artist Fabien Merelle, is displayed in Central, business district of Hong Kong, Tuesday, May 21, 2013. The artwork brings to real life the fantastical and seemingly impossible act of an average man balancing a gigantic elephant. The elephant and the man are modeled on one at the Singapore Zoo and on the artist himself. (Photo by Kin Cheung/AP Photo)

Revelers celebrate New Years Eve in socially distanced pods at Times Square on December 31, 2020, in New York City. On average, about one million revelers are drawn to the Crossroads of the World to watch performances and celebrate the New Year. This year a limited live audience of about 40 first responders and essential workers will be allowed to watch the New Years' ball drop from a secure area in Times Square. (Photo by David Dee Delgado/Getty Images)

Specialist Dilip Patel, left, works at his post on the floor of the New York Stock Exchange, Monday, March 9, 2020. The Dow Jones Industrial Average sank 7.8%, its steepest drop since the financial crisis of 2008, as a free-fall in oil prices and worsening fears of fallout from the spreading coronavirus outbreak seize markets. (Photo by Richard Drew/AP Photo)

Hundreds of people from a range of NGOs and campaign groups protest to demand the immediate restoration of nature at DEFRA – Department for Environment Food & Rural Affairs on September 28, 2023 in London, England. The 2023 State of Nature Report revealed that approximately one in six species in Great Britain, including turtle doves and hazel dormice, are at risk of extinction, citing climate change, intensive farming, and pollution as major threats, with a 19% average decline in monitored plant and animal populations since 1970. (Photo by Guy Smallman/Getty Images)

An Iranian man sells colorful ropes at the Tehrans old Bazaar, the place where the main economy trades take place, in Tehran, Iran, 25 January 2016. Reports state that Iranian officials expected the Iranian economy to grow on an average of eight percent over the coming five years following the lifting of sanctions against Iran. (Photo by Abedin Taherkenareh/EPA)