A dressed up participant without trousers takes part in the 2017 No Pants Subway Ride in New York, the United States, on January 8, 2017. The event, which first took place in New York in 2002, has become a yearly event attended by people in more than 60 cities across the globe. (Photo by Zou Zheng/Xinhua/Sipa USA)

A woman travels on a train stopping at a subway station visited by foreign reporters in central Pyongyang, North Korea on April 14, 2017. (Photo by Damir Sagolj/Reuters)

At the dead of night, the photographer – known to his Instagram followers as Dark Cyanide – heads out to look for hidden gems, like abandoned stations, provisions and tunnels. His intriguing images feature vibrant streaks, graffiti, and tight framing – and by adding individuals to some to some of shots, he is also able to depict the incredible scale of some of the tunnels. Here: Unnamed subway track in New York City. (Photo by Dark Cyanide/Caters News)

A passenger takes off his pants as others not wearing pants dance while waiting for a subway train during the “No Pants Subway Ride” in Mexico City, Mexico, February 21, 2016. The event is an annual flash mob and occurs in different cities around the world, according to its organisers. (Photo by Carlos Jasso/Reuters)

A woman holds a placard that reads, “I am Charlie”, during a vigil to pay tribute to the victims of a shooting by gunmen at the offices of weekly satirical magazine Charlie Hebdo in Paris, at Trafalgar Square in London January 7, 2015. (Photo by Stefan Wermuth/Reuters)

Masked youths face off with French police and gendarmes during a demonstration in Paris as part of nationwide protests against plans to reform French labour laws, France, June 14, 2016. (Photo by Willi Effenberger/Pacific Press/SIPA Press)

Participants gather in the Union Square subway station during the annual No Pants Subway Ride on January 8, 2012 in New York City. The annual event is staged by the group Improv Everywhere which encourages people in dozens of cities worldwide to discard their pants while riding the subway. (Photo by Mario Tama/Getty Images)

Paramedics carry an injured woman out from a subway station after a rush-hour subway train derailment, to be transported by a medical helicopter in Moscow, Russia, on Tuesday, July 15, 2014. A rush-hour subway train derailed in Moscow Tuesday, killing 20 people and injuring at least 150, emergency officials said. Several cars left the track in the tunnel after a power surge triggered an alarm, which caused the train to stop abruptly. (Photo by Ivan Sekretarev/AP Photo)