A Brazilian drug gang member nicknamed Pilintra, 26, poses with a gun atop a hill overlooking a slum in Salvador, Bahia State, April 11, 2013. One of Brazil's main tourist destinations and a 2014 World Cup host city, Salvador suffers from an unprecedented wave of violence with an increase of over 250% in the murder rate, according to the Brazilian Center for Latin American Studies (CEBELA). (Photo by Lunae Parracho/Reuters)

A life-size interactive inflatable sculpture of Stonehenge called “Sacrilege 2012” by English contemporary artist Jeremy Deller on display as part of the “Inflation!” exhibition curated by Mobile M + on April 24, 2013 in Hong Kong. The inflatable artwork is one of six on display as part of the exhibition which is open from April 25, 2013 until June 9, 2013. (Photo by Jessica Hromas)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group attack pushers of spice, a synthetic drug, in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

Sebastião Salgado is a Brazilian documentary photographer living in Paris. He has produced several books, and his work has been exhibited extensively around the world. His latest work, «Genesis», premieres at The Natural History Museum in London on April 11, on view through September 8, 2013. Photo: On South Georgia, a barren island in the far South Atlantic, a pair of southern elephant seal calves beckon before a colony of king penguins. “The male seals can grow to almost five tons,” says Salgado, “but these are just babies. This one looked at me with beautiful eyes”. (Photo by Sebastião Salgado/Amazonas/Contact Press Images)

Emergency personnel respond to the scene of a train derailment in Santiago de Compostela, Spain, on Wednesday, July 24, 2013. A train derailed in northwestern Spain on Wednesday night, toppling passenger cars on their sides and leaving at least one torn open as smoke rose into the air. Dozens were feared dead, with possibly even more injured. (Photo by Antonio Hernandez/AP Photo/El correo Gallego)

A park ranger stands next to a nothern white female rhinoceros named Najin at Ol Pejeta Conservancy, some 290 kms north of the Kenyan capital, Nairobi, on January 27, 2015. Najin is one of only five members of the sub-species left on the planet, three of which reside at Ol Pejeta Conservancy. Conservationists and scientists met in Kenya this week to come up with a last ditch plan to save the northern white rhinoceros from extinction. (Photo by Tony Karumba/AFP Photo)

This green-skinned trio were happy to pose for the camera – with one little frog smiling happily for its close up. The three Reinwardt's Flying Frog, commonly known as the black webbed tree frog or the green flying frog, were spotted playing in a tree by photographer Hendy Mp. The 25-year-old who saw the frogs near his home in Sambas, Kalimantan Barat, in Indonesia, said they reminded him of three brothers playing together. (Photo by Hendy Mp/SOLENT News)

Eighty one-year-old Sakon Haba (L) wearing loin cloth walks past a police station after he bathed in ice-cold water at the Teppozu Inari shrine in Tokyo January 11, 2015. According to organizers, about 100 participants took part in the Shinto ceremony to purify their souls and wish for good health in the new year. (Photo by Toru Hanai/Reuters)