The founder of the UK’s only hobby horse club, Zoe Brown, watches on as members enjoy the activity on July 14, 2025. Brown began running competitions to help her own daughter, 11, feel less shame around her pastime. (Photo by South West News Service)

Actresses perform during the Olympic flame lighting ceremony for the Paris 2024 Olympics Games at the Ancient Olympia archeological site, birthplace of the ancient Olympics in southern Greece, on April 16, 2024. (Photo by Angelos Tzortzinis/AFP Photo)

Ameca, a humanoid robot developed by the British company Engineered Arts Digital, at the Re:publica trade fair in Berlin, Germany on May 28, 2024. (Photo by dts News Agency Germany/Rex Features/Shutterstock)

An Oktoberfest visitor swings her dirndl, at the start of Oktoberfest, on Munich's Theresienwiese, in Germany, Saturday, September 20, 2025. (Photo by Karl-Josef Hildenbrand/dpa via AP Photo)

Switzerland's Zoe Verge-Depre, right, sets up a shot for Esmee Boebner in a beach volleyball match against Canada at the 2024 Summer Olympics, Wednesday, July 31, 2024, in Paris, France. (Photo by Robert F. Bukat/AP Photoy)

A Chinese girl dressed in Qing Dynasty attire takes photographs of another near the Forbidden city in Beijing, China, Sunday, July 21, 2024. (Photo by Vincent Thian/AP Photo)

Amundsen-Scott South Pole Station experiences months of darkness. The sun dips below the horizon on March 21, after which follows several weeks of twilight before complete darkness results. Photo taken on June 25, 2009. (National Science Foundation/Jeremy Johnson)

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.