A member of the “Sibspas” Siberian search and rescue group dressed as Santa Claus (R), waits for his team mate, dressed as Father Frost, the Russian equivalent of Santa Claus, as he climbs the rock named “The Fourth Stolb” (the Fourth Pillar) at the Stolby national nature reserve during a training session of the Russian Emergencies Ministry, outside the Siberian city of Krasnoyarsk, Russia December 15, 2015. (Photo by Ilya Naymushin/Reuters)

Students, dressed in a whole array of fancy dress outfits, were pictured on a wild night out to kick off Freshers' Week in Leeds, England on September 21, 2019. Freshers' Week is a period before the start of an academic year at a university or tertiary institutions. During this period, students participate in a wide range of social activities. (Photo by N B (PRESS) LTD)

A girl has her helmet adjusted on the top of a tank during the Children's Day celebration at a military facility in Bangkok, Thailand January 9, 2016. Army barracks opened their doors to children to interact with their weapons and vehicles as part of the celebration. (Photo by Jorge Silva/Reuters)

A 3-month-old ethnic Tujia baby girl is pictured next to her father as they wait for a traditional ethnic Tujia wedding feast during celebrations marking the Lunar New Year in Ziqiu town, Changyang county of China’s Hubei province, February 15, 2016. (Photo by Jason Lee/Reuters)

A girl collects drinking water at Dala river outside Yangon, Myanmar March 3, 2016. Some 650 million people, or one in 10 of the world's population, have no access to safe water, putting them at risk of infectious diseases and premature death. Dirty water and poor sanitation can cause severe diarrhoeal diseases in children, killing 900 under-five a day across the world, according to United Nations estimates. (Photo by Soe Zeya Tun/Reuters)

A girl calls to her mom as she stands near a dead whale on the shore Monday morning, April 25, 2016, on the cobblestone beach at Lower Trestles on San Onofre State Beach, just south of San Clemente, Calif. (Photo by Jeff Gritchen/The Orange County Register via AP Photo)

Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

A girl washes the body paint off her arm on the shore of Lake Balaton during the coinciding Strand Festival and B.My.Lake Festival in Zamardi, 110 kms southwest of Budapest, Hungary, 24 August 2016. (Photo by Zoltan Balogh/EPA)