A tour group wanders through block 7 of Eastern State Penitentiary in Philadelphia, Pennsylvania April 30, 2014. Opened in 1829, with the original corrective system of “confinement in solitude with labor”, the penitentiary housed about 75,000 inmates in its 142 years of operation. At Eastern State reunions, former inmates, staff and guard gather to share memories and trade stories and get a chance to describe their experiences in question-and-answer sessions with the public. (Photo by Mark Makela/Reuters)

Professional conceptual category winner. Greetings from Mars, by Julien Mauve, France. Mauve says: “I have always wondered what it would be like to discover a totally different world ... and to photograph it for the first time as if I was Ansel Adams. So I came up with this project, which is about space exploration and discovery. But it’s also about our behavior in front of landscapes and how we create pictures that will share our personal story with the world”. (Photo by Julien Mauve)

Rolando Pujol Rodriguez photographed the Cuban raft exodus in 1994, and twenty years later Enrique de la Osa took portraits of some of the people who made it to the United States, in this story which combines archive and present day images. Here: People put the finishing touches to a makeshift boat on a rooftop before lowering it onto a truck and launching it into the Straits of Florida towards the U.S., on the last day of the 1994 Cuban raft exodus in Havana, in this September 13, 1994 file photo. (Photo by Rolando Pujol Rodriguez/Reuters)

Claire Robertson from Scottish Ballet, poses dressed as the Good Snow Flake inside a life size snow globe on Buchanan Street during a promotion for Scottish Ballet’s festive production of The Nutcracker on November 20, 2012 in Glasgow, Scotland. The Nutcracker opens at the Theatre Royal on December the 8th, the production delves deep into the darker reaches of Hoffmann’s original tale in a fresh and vivid retelling of the famous Christmas story. (Photo by Jeff J. Mitchell)

Anand Varma, a U.S. photographer working for the National Geographic, won the First Prize in the Nature Category, Stories, of the 2015 World Press Photo contest with his series of pictures, which includes this one of spores of a fungus landing on an ant, penetrating its exoskeleton and entering its brain, compelling the host to leave its normal habitat on the forest floor and scale a nearby tree, in this picture taken January 22, 2014 and released by the World Press Photo on February 12, 2015. (Photo by Anand Varma/Reuters/National Geographic/World Press Photo)

Vancouver B.C. April 20, 2014 Big Day to celebrate as thousand gathered in front of Vancouver Art Gallery to take part in the 420 Marijuana smoke in here in Vancouver on April 20, 2014. Here lots of free “joints” ready for the big moment. (Photo by Mark van Manen/PNG Staff Photographer/Ian Austin Province News/Vancouver Sun News & Web stories)

Fans of the East German Trabant car gather for their 7th annual get-together on August 23, 2014 in Zwickau, Germany. Hundreds of Trabant enthusiasts arrived to spend the weekend admiring each others cars, trading stories and enjoying activities. The Trabant, dinky and small by modern standards, was the iconic car produced in former communist East Germany and today has a strong cult following. (Photo by Matthias Rietschel/Getty Images)