Visitors look at an elephant swimming in a pool at Khao Kheow Zoo in Chonburi, east of Bangkok, Thailand on February 4, 2020. (Photo by Chaiwat Subprasom/SOPA Images/LightRocket via Getty Images)

An aircraft drops water during a wildfire near Olympia town, western Greece, Thursday, August 5, 2021. Wildfires rekindled outside Athens and forced more evacuations around southern Greece Thursday as weather conditions worsened and firefighters in a round-the-clock battle stopped the flames just outside the birthplace of the ancient Olympics. (Photo by Giannis Spyrounis/ilialive.gr via AP Photo)

The sun sets on Walney Island, Cumbria, county in North West England on October 10, 2019. Today will be unsettled with spells of heavy rain. (Photo by GREENBURN/Alamy Live News)

Lola Aylmer, 25, stands inside the artist Gemma Anderson-Tempini's infinite laundry mirrored room, which is part of a transformed Victorian house, in Leeds, UK early November 2023. (Photo by South West News Service)

Residents gather to watch fireworks rehearsals ahead of the upcoming 100th anniversary of the founding of China's ruling Communist Party in Beijing on Tuesday, June 22, 2021. Chinese authorities have closed Beijing's central Tiananmen Square to the public, eight days ahead of a major celebration being planned to mark the 100th anniversary of the founding of the ruling Communist Party. (Photo by Ng Han Guan/AP Photo)

A model wears a floral headdress at the Royal Horticultural Society's Chelsea Flower show in London, Britain, May 22, 2017. The prestigious Chelsea Flower Show, held annually since 1913 in the Royal Hospital Chelsea grounds, is open to the public from the 23rd to the 27th of May, 2017. (Photo by Dylan Martinez/Reuters)

Photo taken at the top of the Canton Tower, a landmark in Guangzhou, on August 7, 2022 shows the Pearl River running through downtown of Guangzhou, capital of south China's Guangdong Province. (Photo by Liu Dawei/Xinhua News Agency)

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.