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.

Nick Krist makes a funny face as he and his son, Noah, 8, take a selfie before a baseball game between the Los Angeles Angels and the Minnesota Twins, Wednesday, July 22, 2015, in Anaheim, Calif. (Photo by Jae C. Hong/AP Photo)

Divers swim beside millions of silverside fish at Devil's Grotto, Cayman Islands. Swimming in unison, millions of silverside fish dwarf the divers. The fish create waves of silver light as they move around the grottos that lie beneath the surface of the Caribbean Sea. These amazing photographs were captured by Belgian photographer Ellen Cuylaerts, 44, on a diving trip to the Devil's Grotto, Cayman Islands. (Photo by Ellen Cuylaerts/This is Guavo Media)

This picture taken on June 20, 2020 shows longtail macaques chasing a woman on a scooter in the town of Lopburi, some 155km north of Bangkok. Residents barricaded indoors, rival gang fights and no-go zones for humans. Welcome to Lopburi, an ancient Thai city overrun by monkeys super-charged on junk food, whose population is growing out of control. (Photo by Mladen Antonov/AFP Photo)

People in ethnic costumes jump over a bonfire during Ivan Kupala Day celebrations held by the Pripyat River in the town of Turauin Gomel Region, Belarus on July 6, 2020. Ivan Kupala Day, also known as Ivana-Kupala or Kupala Night, is a traditional pagan holiday celebrated in eastern Slavic cultures. Various rituals are traditionally performed on Kupala Night, including making flower wreaths, fortune-telling, jumping over bonfires, and burning a wheel-like effigy symbolizing the sun. (Photo by Natalia Fedosenko/TASS)

Japanese chorus girls appear to be drilling in military tactics atop their theater building as they perform salutes, June 30, 1937. The officer is from the Japanese regular army and says the girls display more rhythm in their drills than do the regular troops. (Photo by AP Photo)

Migrants try to board a truck at Ouistreham ferry port in the hope of reaching the UK on September 12, 2018 in Ouistreham, France. After the clamp down at Calais many young migrants are seeking out new routes to the United Kingdom as stowaways on vehicles making the channel crossing by ferry from French ports. The migrants, of mostly African origin, camp out on the roadside and woodland areas as the authorities prevent the setting up of any camps. (Photo by Christopher Furlong/Getty Images)

A young woman takes pictures of the city with her mobile phone, from the glass-floor observation platform, in the Oriental Pearl Tower, in the financial district of Shanghai, on May 9, 2019. (Photo by Hector Retamal/AFP Photo)