An eight-year-old St Bernard with the longest canine tongue in the world, measuring 18.58cm (7.31in) in length, as recorded by the Guinness World Records: Amazing Animals, in South Dakota, USA. (Photo by Kevin Scott Ramos/GWR/PA Wire)

A golden lion tamarin monkey holds its newly born baby at a zoo in Jerusalem, Thursday, March 22, 2018. Golden lion tamarins are among the rarest animals in the world, according to the World Wildlife Fund. It is listed as endangered according to the International Union for Conservation of Nature. (Photo by Sebastian Scheiner/AP Photo)

A one-horned rhinoceros crosses a road inside Kaziranga national park on the eve of the World Rhino Day in Gauhati, India, Tuesday, September 21, 2021. Kaziranga is home to nearly 2,500 one-horned rhinos and is the world’s largest habitat for the rare animal. (Photo by Anupam Nath/AP Photo)

An Asian elephant cools off at the zoo during the World Elephant Day in Lodz, central Poland, 12 August 2022. The World Elephant Day is observed every year on August 12. (Photo by Grzegorz Michalowski/EPA/EFE/Rex Features/Shutterstock)

An influencer wearing a Barbie inspired dress walks at The Edge observation deck during sunrise on World Photography Day at The Edge at Hudson Yards on August 19, 2023 in New York City. The Edge at Hudson Yards opened for guests earlier than normal for a special World Photography Day Sunrise Event. (Photo by Alexi Rosenfeld/Getty Images)

Team Spain perform their routine during the Team Technical during the World Aquatics Artistic Swimming World Cup 2024 - Stop 2 at Aquatics Centre on May 03, 2024 in Paris, France. (Photo by Adam Pretty/Getty Images)

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.

Actress Anne Hathaway attends the “The Dark Knight Rises” World Premiere at AMC Lincoln Square Theater on July 16, 2012 in New York City. (Photo by Jim Spellman)