Humanoid robots perform at the World Robot Conference 2023 in Beijing, capital of China on August 16, 2023. The World Robot Conference 2023 opened here Wednesday, showcasing cutting-edge achievements and the latest robot industry exhibits. (Photo by Wang Yuguo/Xinhua/Alamy Live News)

Zeebra Lisa Thrower, New Zealand is modelled in the Bizarre Bra Section during the 2023 World of WearableArt Awards Night at TSB Bank Arena on September 22, 2023 in Wellington, New Zealand. (Photo by Hagen Hopkins/Getty Images for World of WearableArt)

Kaori Sakamoto, from Japan, on April 17, 2025 at the ISU World Team Trophy in Figure Skating 2025, held in Tokyo. Teams from all over the world compete in a number of events with two men, two women, one pair and one ice dance entry. (Photo by Yohei Osada/AFLO SPORT via Alamy Live News)

A woman reacts as she joins around a thousand New Year swimmers, many in costume, braved freezing conditions in the River Forth in front of the Forth Rail Bridge during the annual Loony Dook Swim on January 1, 2013 in South Queensferry, Scotland. Thousands of people gathered last night to see in the New Year at Hogmanay celebrations in towns and cities across Scotland. (Photo by Jeff J. Mitchell)

Singapore's Wie Qi Katelin Heng competes in the individual all-around qualification round during the 39th FIG Rhythmic Gymnastics World Championships at the Arena Armeets in Sofia (Arena Armeec hall) on September 14, 2022. (Photo by Nikolay Doychinov/AFP Photo)

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.

Uthen Kukheaw of Thailand in action during a Mixed Doubles Bronze match at the Teqball Tour in Qingdao, China on August 6, 2023. (Photo by Alex Plavevski/EPA/EFE)

Zoi Karangelou of Greece compete in the Women's Solo Technical final on day one of World Aquatics Artistic Swimming World Cup Super Final 2025 at Xi'an Olympic Sports Centre on June 13, 2025 in Xi An, China. (Photo by Lintao Zhang/Getty Images)