International photographic competition, which runs in association with the Royal Botanic Gardens in Kew, London, awards special prize for the best close-up images. Here: Winner – Mayflies by Petar Sabol, Goričan, Croatia. (Photo by Sabol Petar/International Garden Photographer of the Year)

People manoeuvre into position as they take part in a mass nude art installation entitled Sea of Hull by New York based artist Spencer Tunick in Hull, England, Saturday July 9, 2016. (Photo by Danny Lawson/PA Wire via AP Photo)

A rider demonstrates Lighting artist Bruce Munro latest installation “Star-Turn” at a one-night event in front of the Holburne Museum on December 21, 2011 in Bath, England. (Photo by Matt Cardy/Getty Images)

A sign is posted in front of the new Yoga Room at San Francisco International Airport's terminal two on January 26, 2012 in San Francisco, California. (Photo by Justin Sullivan/Getty Images)

A worker paints a santon, the typical figurines from Provence, at the Marcel Carbonel's Santon factory in Marseille, November 28, 2016. Santons are traditional hand-colored figurines usually set in Christmas Nativity scenes. (Photo by Jean-Paul Pelissier/Reuters)

In the works of a photographer named Dave – who goes by Freaktography and never gives out his full name – haunting abandonment leaps from images of discarded machinery, tools and factory essentials. (Photo by Freaktography/Caters News Agency)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

Marc Berthod of Switzerland during the Audi FIS Alpine Ski World Cup Men's Super Combined on February 12, 2012 in Sochi, Russia. (Photo by Vianney Thibaut/Agence Zoom/Getty Images)