A Russian Rosguardia (National Guard) servicemen secures an area as a massive blaze seen over the Crocus City Hall on the western edge of Moscow, Russia, Friday, March 22, 2024. Several gunmen have burst into a big concert hall in Moscow and fired automatic weapons at the crowd, injuring an unspecified number of people and setting a massive blaze in an apparent terror attack days after President Vladimir Putin cemented his grip on the country in a highly orchestrated electoral landslide. (Photo by Dmitry Serebryakov/AP Photo)

Russian Communist party activists and supporters carry portraits of Soviet founder Vladimir Lenin (R) and Soviet dictator Josef Stalin (L) as they attend a flowers-laying ceremony at the Lenin's Mausoleum on Red Square in downtown Moscow on November 7, 2021, marking the 104th anniversary of the Bolshevik Revolution also known as the October Revolution. (Photo by Dimitar Dilkoff/AFP Photo)

Domestic tourists visit the beach at Wonsan Kalma Coastal Tourist Area in Wonsan, North Korea's Kangwon Province on July 1, 2025. North Korea opened a massive resort area on its east coast, state media said on July 2, with the tourism pet project of leader Kim Jong Un reportedly set to welcome Russian guests later this month. (Photo by Kim Won Jin/AFP Photo)

A doll dressed in Ukraine's national dress lies on the floor amid broken glass inside a kindergarten destroyed by a missile strike, in Kyiv on July 10, 2024, amid the Russian invasion in Ukraine. Russia struck cities across Ukraine on July 8, 2024, with a missile barrage that killed 33 people and ripped open a children's hospital in Kyiv. (Photo by Anatolii Stepanov/AFP Photo)

Russian-born artist Vlad Korneev poses for a picture in his museum called “Designpanoptikum, Museum For Extraordinary Objects” on November 4, 2010 in Berlin, Germany. The museum displays objects whose outward appearance was determined by function rather than form, he says, and are the result of a collection he started while accumulating props for his photographic works. (Photo by Sean Gallup/Getty Images)

ESA astronaut Paolo Nespoli looks on after landing back on Earth from their Soyuz TMA-20 spacecraft on May 24, 2011 in Zhezkazgan, Kazakhstan. The mission of the Soyuz TMA-20 was launched last December to the International Space Station with the flight engineers Catherine Coleman from the United States, Russian cosmonaut Dmitry Kondratyev and Italian astronaut Paolo Nespoli. The next expedition is expected to launch this June. (Photo by Stephane Corvaja/ESA via Getty Images)

A Ukrainian serviceman who fought in Debaltseve is seen near Artemivsk February 19, 2015. Fighting raged in eastern Ukraine on Thursday despite European efforts to resurrect a still-born ceasefire, a day after pro-Russian separatists who spurned the truce forced thousands of government troops out of a strategic town. (Photo by Gleb Garanich/Reuters)

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.