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 South Korea university student gets her head shaved during a protest against Japan's decision to release contaminated water from its crippled Fukushima nuclear plant into the sea, in front of the Japanese embassy, in Seoul, South Korea, April 20, 2021. (Photo by Kim Hong-ji/Reuters)

A shepherd and his flock in the Bitlis province of eastern Turkey in the first decade of April 2024. Shepherds regularly embark on gruelling journeys through the dusty outback, as they take their sheep to the high plateaus needed for grazing and then back to villages for milking. (Photo by Kahraman Kaya/Solent News)

Indian School children's in a traditational attire of a characters of Indian epic Ramayan, on the eve of children's day celebration at cubbon park, in Bangalore, India, 13 November 2016. Children's day (also known as Bal Divas), in India is celebrated every year on 14th of November to increase the awareness of people towards the rights, care, and education of children. Many schools hold activities and allow students to have fun and attend their classes in coloured dresses. (Photo by Jagadeesh N.V./EPA)

A penguin (Manchots Royaux) walks on the basement area, early morning on December 25, 2022, at the Kerguelen Islands, also known as the Desolation Islands, are a group of islands in the sub-Antarctic. (Photo by Patrick Hertzog/AFP Photo)

A cat dressed in a traditional outfit takes part during the Orthodox Christmas celebration in Kiev, Ukraine on January 7, 2020. Orthodox Christians celebrate Christmas Day on December 25 of the older Julian calendar, which currently corresponds to January 7 in the Gregorian calendar. (Photo by Pavlo Gonchar/SOPA Images/LightRocket via Getty Images)

A woman prepares to release carps to Hoan Kiem lake on Kitchen God's Day as part of the traditional Vietnamese Lunar New Year celebrations, the biggest festival of the year in Hanoi, Vietnam on February 4, 2021. (Photo by Kham via Reuters)

Sara Moni, dressed as the World of Warcraft's Sinestra, poses for photographers on day three of the Comic-Con International held at the San Diego Convention Center Saturday July 23, 2016 in San Diego. (Photo by Denis Poroy/Invision/AP Photo)