A woman aims a World War II machine gun at a military show during celebration of the Defenders of the Fatherland Day in St.Petersburg, Russia, Tuesday, February 23, 2016. The day, celebrated in Russia on February 23, honors the nation's military and is a nationwide holiday. (Photo by Dmitri Lovetsky/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)

A thirsty timber wolf, Lithuania, 2018. (Photo by Erikas Plucas/Alamy Stock Photo)

Internationally acclaimed German three-dimensional artist Manfred Stader adds finishing touches to his artwork in Cape Town, South Africa on 21 November 2010. Stader created this masterpiece to celebrate the opening of Speedo's first dedicated concept store in Africa. (Photo by Foto24/Gallo Images/Getty Images)

Khloe Kardashian and Kris Jenner exit a studio in LA with Lisa Rinna, Kyle Richards, and a film crew. (Photo by Backgrid USA)

This image released by Disney shows Mena Massoud as Aladdin, left, and Will Smith as Genie in Disney's live-action adaptation of the 1992 animated classic “Aladdin”. (Photo by Daniel Smith/Disney via AP 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)

Anthony Joshua punches Kubrat Pulev during the IBF, WBA, WBO and IBO World Heayweight Title fight between Anthony Joshua and Kubrat Pulev at The SSE Arena, Wembley on December 12, 2020 in London, England. A limited number of fans (1000) are welcomed back to sporting venues to watch elite sport across England. This was following easing of restrictions on spectators in tiers one and two areas only. (Photo by Andrew Couldridge – Pool/Getty Images)