Aerial view of people circling around bonfires to celebrate the Torch Festival on Axilixi Prairie on July 20, 2024 in Bijie, Guizhou Province of China. (Photo by Luo Dafu/VCG via Getty Images)

Sunrise over the River Thames and Tower Bridge in London today morning on January 28, 2024. It has been forecast that Sahara dust will be in the atmosphere. (Photo by Alister Gooding/Picture Exclusive)

Brown-throated sloth called “43”, rescued by Juan Carlos Rodriguez and his wife Haydee in a residential area, waits in the kennel getting prepared for being released, at the couple's shelter for sloths, in San Antonio, Venezuela on July 30, 2021. (Photo by Leonardo Fernandez Viloria/Reuters)

Caterine Ibarguen of Team Colombia competes in the Women's Triple Jump Qualification on day seven of the Tokyo 2020 Olympic Games at Olympic Stadium on July 30, 2021 in Tokyo, Japan. (Photo by Matthias Hangst/Getty Images)

A column of sand and front of clouds are seen by dash cam as the car drives near a tornado in Dragalina, Calarasi county, Romania April 30, 2019 in this still image taken from a video obtained from social media. (Photo by Alexandra Puscasu via Reuters)

Seljalandsfoss waterfall, located in Iceland. Seljalandsfoss is one of the most famous waterfalls of Iceland. This waterfall of the river Seljalandsá drops 60 metres (200 ft) over the cliffs of the former coastline. It's possible to go behind the waterfall. (Photo by HotSpot Media)

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)