Valentyna Konstantynovska, 79 years-old, holds a weapon during basic combat training for civilians, organized by the Special Forces Unit Azov, of Ukraine's National Guard, in Mariupol, Donetsk region, eastern Ukraine, Sunday, February 13, 2022. The United States is evacuating almost all of the staff from its embassy in Kyiv as Western intelligence officials warn that a Russian invasion of Ukraine is increasingly imminent. (Photo by Vadim Ghirda/AP Photo)

Girls in red neckerchiefs dance on Red Square, with the GUM, the State Department Store and the Historical Museum in the background, during a ceremony to celebrate joining the Pioneers organization and 100th anniversary of the All-Union Pioneer Organization, in Moscow, Russia, Sunday, May 22, 2022. Pro-Communist Russians are trying to preserve the Young Pioneers, which used to be the Communist league for pre-teens in the Soviet Union. (Photo by AP Photo/Stringer)

Tupolev Tu-142MK, a Soviet and Russian maritime reconnaissance and anti-submarine warfare aircraft flies above a statue of Soviet Union founder Vladimir Lenin during a rehearsal of the Naval parade in St.Petersburg, Russia, Thursday, July 28, 2022. The celebration of Navy Day in Russia is traditionally marked on the last Sunday of July and will be celebrated on July 31 this year. (Photo by Dmitri Lovetsky/AP Photo)

Russian Il-76 military transport aircrafts fly in formation during a rehearsal for the flypast, which marks the 75th anniversary of the victory over Nazi Germany in World War Two, in Moscow, Russia on May 4, 2020. The traditional large-scale Victory Day military parade across Red Square was postponed due to the outbreak of the coronavirus disease (COVID 19). (Photo by Maxim Shemetov/Reuters)

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)

Iraqi army soldiers warm themselves next to a fire near the Qayara air base, south of Mosul, Iraq, Tuesday, November 1, 2016. The U.N. human rights office is lauding efforts by the U.S.-led coalition in the battle against the Islamic State group in Mosul. The office in Geneva says coalition flights over Iraq have largely succeeded in preventing IS from bringing in 25,000 more civilians to the city center, where the militant group has been using people as human shields as Iraqi forces advance on Mosul. (Photo by Felipe Dana/AP 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.