Eleonora Brunacci and Mariano Di Vaio walk the red carpet ahead of the “Racer And The Jailbird (Le Fidele)” screening during the 74th Venice Film Festival at Sala Grande on September 8, 2017 in Venice, Italy. (Photo by Pascal Le Segretain/Getty Images)

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)

A Typhoon jet flown by Flt Lt Jim Peterson practising over RAF Coningsby in the East Lindsey district of Lincolnshire, England on September 27, 2019 producing a rainbow effect over the plane. The rainbow is made of crystalized or frozen water vapor that reflect and refract sunlight, causing the rainbow effect. (Photo by Claire Hartley/Bav Media)

Carnival revelers perform during the Academicos do Baixo Augustaa carnival “bloco” parade in Sao Paulo, Brazil, Sunday, February 24, 2019. (Photo by Andre Penner/AP Photo)

A woman sits behind a bicycle on a cold winter morning in New Delhi, December 31, 2019. (Photo by Anushree Fadnavis/Reuters)

Irish actress Jessie Buckley in Miu Miu attends the EE British Academy Film Awards 2020 at Royal Albert Hall on February 02, 2020 in London, England. (Photo by Jamie Simonds/Bafta/Rex Features/Shutterstock)

Actresses from left Jurnee Smollett-Bell, Rosie Perez, Mary Elizabeth Winstead, Margot Robbie and Ella Jay Basco pose for a selfie photo upon arrival at the world premiere of “Birds of Prey” in London, Wednesday, January 29, 2020. (Photo by Joel C. Ryan/Invision/AP Photo)