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.

A Tamil devotee prays during the Thai Pongal harvest festival at a temple in Colombo January 15, 2016.The Tamil festival of Thai Pongal is a thanksgiving ceremony in which the farmers thank the spirits of nature, the sun and the farm animals for their assistance in providing a successful harvest. (Photo by Dinuka Liyanawatte/Reuters)

An Indian Army soldier marches next to a tableau during the Republic Day parade in New Delhi, India, January 26, 2016. India celebrated its Republic Day Tuesday, highlighted by a march by different branches of the military as well as a display of arms and missiles. (Photo by Adnan Abidi/Reuters)

Russian soldiers from 34th motorized infantry mountain brigade, 58th Army, prepare to evacuate a fellow soldier acting as an injured person during a drill at the Darial range outside Russia's city of Vladikavkaz, July 28, 2010. (Photo by Kazbek Basayev/Reuters)

A farmer seen harvesting his crops while Mount Sinabung spewing out volcanic ash on July 4, 2017 in North Sumatera, Indonesia. The increased volume of lava dome that reaches one million eight hundred cubic meters, said volcanologist, through radio communications, do not dampen the activities of the people around sinabung, such as farming, harvesting their crops, picking up objects that are still left behind, or just take a picture while walking around near mount Sinabung. (Photo by Sabirin Manurung/Pacific Press/Barcroft Images)

A participant in the 5th Lady on Bicycle annual festival opens her bag in the back basket of her tricycle in the Sokolniki park in Moscow on August 6, 2017. The festival's aim is to capture the city's fashionable women on vintage style bicycles. (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)

In this Monday, January 23, 2017 photo, chicken feet snacks shop owner Leung Kin-kung testes a chicken feet in Hong Kong. Saturday marks the start of the lunar Year of the Rooster and families in China will reunite for festivities, fireworks and food. While tradition calls for feasting on “auspicious” foods, many will also munch on staple snacks like “phoenix claws”, the Chinese name for chicken feet. (Photo by Vincent Yu/AP Photo)