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 schoolgirl reacts as she wades through a flooded street during heavy rain showers in Mumbai on August 18, 2025. (Photo by Punit Paranjpe/AFP Photo)

An Armenian serviceman fires a cannon towards Azerbaijan positions in the self-proclaimed Republic of Nagorno-Karabakh, Azerbaijan, Tuesday, September 29, 2020. (Photo by Sipan Gyulumyan/Armenian Defense Ministry Press Service/PAN Photo via AP Photo)

A hot air balloon floats over farm fields south of Washington, Ill., as the sun slips behind clouds on the autumn afternoon of Wednesday, September 24, 2014. (Photo by Ron Johnson/AP Photo/Peoria Journal Star)

In this March 31, 2019 photo, an Egyptian student borrows a Bedouin wedding dress to pose for a photograph with Bedouin men from the Hamada tribe, in Wadi Sahw, Abu Zenima, in South Sinai, Egypt. Four Bedouin women are for the first time leading tours in Egypt’s Sinai Peninsula, breaking new ground in their deeply conservative community, where women almost never work outside the home or interact with outsiders. The tourists can only be women, and the tours can’t go overnight. Each day before the sun sets, the group returns to the Hamada’s home village in Wadi Sahu, a narrow desert valley. (Photo by Nariman El-Mofty/AP Photo)

Models prepare backstage ahead of the “Romance Was Born” show during Afterpay Fashion Week Australia Resort 22 Collections at Carriageworks on May 31, 2021 in Sydney, Australia. (Photo by Jessica Hromas/The Guardian)

In this photograph taken on August 25, 2016, an Afghan shepherd watches over his sheep as they graze on the outskirts of Herat. (Photo by Aref Karimi/AFP Photo)

Dani Alves of Paris Saint-Germain and Spanish model Joana Sanz are pictured inside the photo booth prior to The Best FIFA Football Awards at Royal Festival Hall on September 24, 2018 in London, England. (Photo by Michael Regan – FIFA/FIFA via Getty Images)