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)

Demonstrators are seen running for shelter from a protest against plans for new austerity measures October 19, 2011 in Athens, Greece. Greece's largest labor unions have called for a 48-hour strike, while the Socialist government is beginning to push through legislation for cost cutting reforms. (Photo by Milos Bicanski/Getty Images)

An octopus is filmed by the National Oceanic and Atmospheric Administration ship Okeanos Explorer and its robotic sub. (Photo by National Oceanic and Atmospheric Administration)

Whole cooked alligators are displayed before being served at the 110th Explorers Club Annual Dinner at the Waldorf Astoria in New York March 15, 2014. The club, which promotes the scientific exploration of land, sea, air and space featured catering by chef and exotic creator Gene Rurka. Chef Rurka prepared a variety of dishes featuring an array of insects, wildlife, animal body parts and invasive species. (Photo by Andrew Kelly/Reuters)

A general view of the Cathedral on the Blood on November 2, 2011 in Yekaterinburg, Russia. Yekaterinburg is one of thirteen cities proposed as a host city for 2018 FIFA World Cup in Russia. (Photo by Harry Engels/Getty Images)

«Underwater». Laurie Simmons discovered this silicone sеx doll in a shop while on holiday in Japan and was immediately interested in the type of generic beauty their looks could add to her work. She went on to create the Love Doll series, in which she places silicone sеx dolls in positions that explore a woman’s interior life. (Photo by Laurie Simmons/Salon 94/The Guardian)

A prototype of the Space Exploration Technologies Corp. (SpaceX) Starship launch vehicle stands during an event at the SpaceX launch facility in Cameron County, Texas, U.S., on Saturday, September 28, 2019. Elon Musk gave space fans an update Saturday evening on the status of “Starship”, the next-generation vehicle his SpaceX plans to use to eventually take humans to Mars. (Photo by Callaghan O'Hare/Reuters)

An attendee at the “Eating Insects Detroit: Exploring the Culture of Insects as Food and Feed” conference at Wayne State University shows an edible freeze-dried locust insect in Detroit, Michigan May 26, 2016. (Photo by Rebecca Cook/Reuters)