A Russian trenchmortar crew run to take up a new firing position in the Stalingrad area during the Great Patriotic War. (Photo by Keystone/Getty Images). October 1942

A woman looks at a swimmer getting herself warm after the annual Christmas winter swimming competition in the Vltava river in Prague December 26, 2014. (Photo by David W. Cerny/Reuters)

In a handout picture released by the British Ministry of Defence via their Defence News Imagery website on August 22, 2016, Nils Olav the penguin inspects the Guard of Honour formed by His Majesty the King of Norway's Guard on August 22, 2016 at Edinburgh Zoo in Scotland. His Majesty the King of Norway's Guard paid a very special visit to RZSS Edinburgh Zoo to bestow a unique honour upon resident king penguin Sir Nils Olav. Already a knight, the most famous king penguin in the world was given the new title of “Brigadier Sir Nils Olav”. (Photo by Mark Owens/AFP Photo)

Oscar winner Charlize Theron explodes into summer in “Atomic Blonde”, a breakneck action-thriller that follows MI6’s most lethal assassin through a ticking time bomb of a city simmering with revolution and double-crossing hives of traitors. (Photo by Jonathan Prime)

Britain's Princess Elizabeth clasps her hands in sympathy as Sergeant Jean Bayliss faints at her feet during an inspection of the guard of honour of the Women's Royal Army Corps at Shrewsbury Castle, Shropshire, on July 6, 1949. (Photo by AP Photo)

Dinah Jane, from left, Normani Kordei, Lauren Jauregui, and Ally Brooke of Fifth Harmony perform a medley at the MTV Video Music Awards at The Forum on Sunday, August 27, 2017, in Inglewood, Calif. (Photo by Chris Pizzello/Invision/AP Photo)

To an outsider, their passion is at times illegal and often on the verge of life and death. But climbing rooftops of high-rise buildings and exploring abandoned facilities is in the blood of these young Muscovites. The small group calls itself “Rudex”, which stands for “roof and decay exploration”, and is akin a Western youth craze known as urbex or “urban exploration” of man-made structures. Here: Urban explorer Vad Him of Rudex team jumps whilst on a rooftop in Moscow, Russia, August 14, 2017. (Photo by Maxim Shemetov/Reuters)