Armed man stand at entrance of the naval headquarters in Sevastopol, March 19, 2014. Around a dozen Ukrainian servicemen, unarmed and in civilian clothes, walked out of the Ukrainian naval headquarters in the Crimean port of Sevastopol on Wednesday after it was taken over by pro-Russian forces, a Reuters witness said. (Photo by Baz Ratner/Reuters)

“This is a shot I have envisioned in my head for a while, and only possible to shoot today with the invention of the GoPro. Shot at a beach break near my home. The board broke on this wave, but the vision made it worthwhile. Shot with the GoPro Hero 3+ and a Gripstick Pro Mount”. (Photo and caption by Mike Coots)

An aspiring witch performs during auditions the new witch of Wookey Hole Caves during trials held at the Somerset tourist attraction, on October 22, 2013. Around 50 applicants took part in the auditions today for a £50,000 a year (pro rata) job as the face of Wookey Hole. (Photo by Tim Ireland/PA Wire)

Ireland's Philip Mulpeter, left, is kicked by Brazilian Vitor Nobrega during their welterweight mixed martial arts bout of International Pro Combat at the Estoril Casino in Estoril, near Lisbon, Portugal, Monday, January 26, 2015. Nobrega defeated Mulpeter. (Photo by Francisco Seco/AP Photo)

A man cries over the body of his girlfriend, who was killed by shelling in the Kalininsky district of Donetsk, territory under control of the pro-Russian Government of the Donetsk People's Republic in eastern Ukraine, Thursday, June 9, 2022, during the Russian invasion. (Photo by Alexei Alexandrov/AP Photo)

Twelve-year-old Kelia Gallina of French Polynesia after surfing in Heat 1 of the Elimination Round at the Lexus Tahiti Pro on August 8, 2025 at Teahupoo, Tahiti, French Polynesia.(Photo by Brent Bielmann/World Surf League via Getty Images)

Cristiano Ronaldo of team Al-Nassr FC scores their fourth goal during the Saudi Pro League match between Al Nassr and Al Khaleej at Al Awwal Park on November 23, 2025 in Riyadh, Saudi Arabia. (Photo by Abdullah Ahmed/Getty Images)

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.