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)

Israelis sit by as a man poses while jumping into the pool of the natural water spring of Ein al-Faraah near the Palestinian village of Doura, west of Hebron in the occupied West Bank, during the Jewish religious holiday of Sukkot (Feast of the Tabernacles) on October 17, 2019. (Photo by Hazem Bader/AFP Photo)

A man photographs Anila Quayyum Agha's “Intersections” art work on the first day of ArtPrize at the Grand Rapids Art Museum in Grand Rapids, Mich. on Wednesday, September 24, 2014. (Photo by Emily Rose Bennett/AP Photo/The Grand Rapids Press)