A Uyghur boy sits atop a horse as he has his picture taken outside the Id Kah Mosque before the Eid holiday on July 28, 2014 in old Kashgar, Xinjiang Province, China. Nearly 100 people have been killed in unrest in the restive Xinjiang Province in the last week in what authorities say is terrorism but advocacy groups claim is a result of a government crackdown to silence opposition to its policies. China's Muslim Uyghur ethnic group faces cultural and religious restrictions by the Chinese government. Beijing says it is investing heavily in the Xinjiang region but Uyghurs are increasingly dissatisfied with the influx of Han Chinese and uneven economic development. (Photo by Kevin Frayer/Getty Images)

People walk through Ginza’s shopping district in Tokyo, Japan, 15 December 2025. Japan’s economic focus is on the upcoming Bank of Japan (BOJ) meeting where the central bank is expected to raise its policy rate to combat inflation. The BOJ signaled a rate hike bar is cleared with the wage momentum still intact. (Photo by Franck Robichon/EPA)

Rohingya refugee sisters Nur Kaida (R) and Ruhana hug each other at their shelter at the Palongkhali refugee camp near Cox's Bazar, Bangladesh December 21, 2017. (Photo by Marko Djurica/Reuters)

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)

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)

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 tribal fighter loyal to Yemen's government stands in Al Khurais village of Nihm district east of the capital Sanaa January 11, 2016. (Photo by Ali Owidha/Reuters)