An old woman smokes a cigar at Old Havana's Plaza de la Catedral on February 07, 2006 in Havana, Cuba. (Photo by Marco Prosch/Getty Images)

Five-year-old Julia cuddles a free teddy bear at a toy adoption station in a branch of Dobbies in Wallington, UK on December 4, 2023. Research shows almost half of parents (46%) in Britain plan to spend less on their children’s Christmas presents this year, and 47% believe their child would not mind receiving a preloved toy as a gift. (Photo by Michael Leckie/PA Wire Press Association)

A boy and a woman run across a railway track as a train approaches in Chengdu, Sichuan province, China, October 8, 2015. Many residents disregard sign prohibiting this kind of illegal crossing and choose to do so to save time, local media reported. (Photo by Hao Fei/Reuters/Western China Metropolis Daily)

People in quarantine exercise in front of their homes amid Covid-19 full lockdown of the city in Shanghai, China, 27 April 2022. According to the Shanghai Health Commission on 27 April, there were 48 new Covid-19 deaths, 1,606 locally transmitted cases, and 11,956 local asymptomatic infections, in Shanghai city. Despite the death toll rising in Shanghai, the number of daily infections has gradually declined. (Photo by Alex Plavevski/EPA/EFE)

Relatives mourn over the shrouded body of Mohammad Abed, who is killed in an Israeli airstrike on a shelter in Gaza City, during his funeral in Gaza City, on April 19, 2025. (Photo by Majdi Fathi/NurPhoto/Rex Features/Shutterstock)

Honor guards are viewed during an official welcoming ceremony for Turkish President Recep Tayyip Erdogan by Albanian President Bajram Begaj, in Tirana, Albania on October 10, 2024. Turkish President Recep Tayyip Erdogan was welcomed by Albanian President Bajram Begaj with an official ceremony ahead of their meeting. (Photo by Mehmet Ali Ozcan/Anadolu via Getty Images)

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)

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.