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.

U.S. President elect Barack Obama kisses his wife Michelle as Vice-President elect Joe Biden (right) embraces his wife Jill after Obama gave his victory speech during an election night gathering in Grant Park on November 4, 2008 in Chicago, Illinois. (Photo by Scott Olson/Getty Images)

President Barack Obama watches as Joey Hudy (L), 14, from Phoenix, Arizona pumps the Extreme Marshmallow Cannon he invented, while touring student science fair projects on exhibit in the State Dining Room at the White House February 7, 2012 in Washington, DC. Obama hosted the second White House Science Fair celebrating the student winners of science, technology, engineering and math (STEM) competitions from across the country. (Photo by Molly Riley-Pool/Getty Images)

Iranian soccer fan wait for the start of the group B match between Iran and Spain at the 2018 soccer World Cup in the Kazan Arena in Kazan, Russia, Wednesday, June 20, 2018. (Photo by Diego Azubel/EPA/EFE)

A contestant prepares at the backstage before the Miss Transqueen India 2018 transgender beauty pageant in Mumbai, India on October 7, 2018. (Photo by Francis Mascarenhas/Reuters)

An Iraqi army cadet performs “the leap of faith” from a bridge in Baghdad, September 22, 2015. (Photo by Ahmed Saad/Reuters)

Hong Kong art gallery director Sarah Greene said that Wolf, known for his work depicting mega-cities, has died Tuesday, April 24, 2019 night at his home. She said he was 64. Wolf won first prize in the World Press Photo competition in 2005 and 2010. Here: Architecture of Density #119, 2009. (Photo by Michael Wolf, courtesy of Flowers Gallery)

Figurines of former pro-Russian separatist commander Igor Strelkov from the collection entitled “Toy Soldiers of Novorossiya” are on display at a workshop in Moscow August 29, 2014. A Moscow-based maker of toy soldiers has sought inspiration for his creations from Ukrainian rebels fighting government troops in the east of Ukraine. Toy soldier maker, Timur Zamilov, displayed his new collection of rebel fighters cast in metal on Friday, before they are due to go on sale. His new collection is entitled “Toy Soldiers of Novorossiya” (New Russia), a reference to regions in eastern Ukraine where pro-Russian separatist fighters want full independence. Zamilov's selection includes models of Cossack soldiers, volunteers, soldiers bearing anti-aircraft missiles and even a miniature of prominent rebel leader Igor Strelkov. (Photo by Sergei Karpukhin/Reuters)