An aurora is seen in the sky in Pajala, Sweden on February 10, 2022. (Photo by Alexander Kuznetsov/Reuters)

Members of the London Fire Spinners group meet once a month, pictured at Gabriel's Wharf along the River Thames, UK. A collective of glow and fire performers with extensive performance experience. Dated on March 14, 2025. (Photo by Kevin Jay/Picture Exclusive)

Sandy Bell stands with her golden doodle dog Ozzy looking out at the golden sunrise breaking through the tree on a cold and frosty morning at Bowden Loch near Melrose in the Scottish Borders, South Scotland on February 7, 2025. (Photo by Phil Wilkinson/The Times)

A cyclist rides past a tumulus tomb in Gyeongju, South Korea on November 1, 2025. (Photo by Anthony Wallace/AFP Photo)

Paul Kerr was able to capture this stunning vista of the aurora australis from Canberra, New Zealand on June 1, 2025. (Photo by Paul Kerr/Hold Still Photography)

Passengers wear no trousers as they ride the London Underground in London, Britain, 07 January 2018. The No Pants Subway Ride is an global annual event where people take the public transport while they are not wearing trousers to surprise other passengers. This event takes place on the first Sunday of every year in the world's major cities. (Photo by Tolga Akmen/EPA/EFE/Rex Features/Shutterstock)

A man dressed as Santa Claus skateboards down Fifth Avenue towing a dog before the annual Christmas tree lighting ceremony at Rockefeller Center in New York on December 5, 2019. (Photo by John Angelillo/UPI/Barcroft Media)

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.