A man looks at a mural painted on the walls of houses in Zaraeeb, created by French-Tunisian artist El Seed, in the shanty area known also as Zabaleen or “Garbage City” on the Mokattam Hills in eastern Cairo, Egypt, April 4, 2016. (Photo by Amr Abdallah Dalsh/Reuters)

People walk on the street in Samara, Russia on July 18, 2017. (Photo by David Mdzinarishvili/Reuters)

Singer Jason Derulo performs during his Flash Mob with Knicks City Dancers outside of Madison Square Garden on September 28, 2011 in New York City. (Photo by Mike Coppola/Getty Images)

Girls look at a newly installed “Renew” media point in the City of London on January 26, 2012 in London, England. The “pods” will transmit each market day and will include breaking news, weather and travel information, and information about sport, fashion, the arts and entertainment. The stations which will also double as recycling points are run by media company Renew. (Photo by Dan Kitwood/Getty Images)

This computer image provided Monday March 17, 2014 by the Press Office of socialist candidate to Paris Mayor Anne Hidalgo, shows a tunnel of abandoned railway from the 19th century, now ramshackle and overgrown, turned into a cinema. Hidalgo’s plan envisions not just a green space but in the tunnels, places for farming fish and mushrooms. (Photo by AP Photo/Anne Hidalgo's Press Office)

The Upside Down Room, with furniture on the ceiling and real beds and chairs that open out of the floor, is one of many creative and even bizarre rooms shown photographed February 14, 2002 at the Propeller Island City Lodge in Berlin, Germany. Owner, artist and musician Lars Stroschen designed the rooms of the hotel, which has 28 rooms and has been open since June, 2001. (Photo by Sean Gallup/Getty Images)

Revelers march during the Greenwich Village Halloween Parade, Tuesday, October 31, 2017, in New York. (Photo by Andres Kudacki/AP Photo)

Scared of Heights. “Taken from the highest residential building in Asia: the Zenith in Busan. This was taken with official permission (which took me months to get) and safety measures were taken. I had to hang myself over the edge to get this shot. Not for the faint of heart! But when you’re at a height like this, the world below you just seems different. It takes away the fear one would normally have, and gives a sense of peace instead”. (Photo by Albert Dros/NatGeo Cities Travel Photographer of the Year 2017)