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)

Promotional models use their smartphones during their break at the Global Mobile Internet Conference in Beijing May 6, 2014. Mobile Internet industry executives, developers and investors from more than 30 countries took part in the Global Mobile Internet Conference in Beijing, the organiser said. (Photo by Kim Kyung-Hoon/Reuters)

An attendee dances at the start of the “Big Goth Dance Party” during the Porcupine Freedom Festival, or PorcFest, the Free State Project's annual summer gathering in Lancaster, NH on Wednesday, June 25, 2014. (Photo by Matthew Cavanaugh/The Washington Post)

“Originally published in the April 9, 1951, issue of LIFE magazine, W. Eugene Smith’s photo essay, «Spanish Village», has been lauded for more than six decades as the most moving photographic portrait ever made of daily life in rural Spain during the rule of dictator Francisco Franco”. – Time & Life Pictures. Photo: His wife, daughter, granddaughter and friends have their last earthly visit with a villager. (Photo by W. Eugene Smith/Time & Life Pictures)

“These eerie formations in the sky may look like alien ships. But as the Daily Mail points out, they’re actually a natural occurrence called lenticular clouds”. – Claudine Zap. Photo: Lenticular clouds hover of the mountains of the Kamchatka Peninsula in Russia. (Photos by Denis Budkov/Caters News)

These incredible images capture the immense detail of waves beautifully crashing into the serene waters of Hawaii. (Photo by Bryce Groark/Caters)

Located at the foot of the Rocky Mountains on the North Saskatchewan River, the rare phenomenon occurs each winter in the man-made lake. Photo: Ice bubbles in Abraham Lake. (Photo by Chip Phillips/Rex Features)

Horse racing is part of Naadam, a festival organized every July in Mongolia to celebrate the People’s Revolution. Using children as jockeys in such races has a centuries-long tradition. Boys and girls as young as 5 (although the law imposes a minimum age limit of 7) ride in races that can be dangerous, with hundreds of horses running across the steppe at distances of 12 to 28 kilometres at great speeds. (Photo by Tomasz Gudzowaty)