A man washes his horse as a woman bathes her son at concrete water pens under a flyover in a slum area in Kolkata, India October 21, 2016. (Photo by Rupak De Chowdhuri/Reuters)

Models backstage at the Lagos Fashion & Design Week in Nigeria on October 26, 2016. The opening night attracted models, buyers, consumers and the media to view the latest creations by African designers, five of whom were showcasing plus-size collections in the Nigerian city. (Photo by Stefan Heunis/AFP Photo)

Japan's On-Art Corp's eight metre tall dinosaur-shaped mechanical suit robot “TRX03” performs during its unveiling in Tokyo, Japan November 10, 2016. Stomping and roaring dinosaurs took to the stage in Tokyo on Thursday as part of a presentation for a proposed entertainment park where visitors will be able to see the realistic replicas first-hand. Japanese firm ON-ART Corp. unveiled man-operated robotic models of raptors, an allosaurus and a tyrannosaurus rex, in a performance at a hotel hall. (Photo by Toru Hanai/Reuters)

Shimmering clearest blue and stretching as far as the eye can see, this is one of Iceland's famed crystal ice caves. The giant solid waves look frozen in time but they are slowly moving along as part of the Vatnajokull Glacier – which stretches across eight per cent of the island. The images were captured in February 2014 by British photographer Rob Lott, 49. Photo: A wide view of Rob Lott in the crystal ice cave in the Vatnajokull Glacier, Iceland. (Photo by Rob Lott/Barcroft Media)

A young Balinese man tries to kiss a woman during the Kissing Festival known as “Omed-Omedan” at Sesetan village on April 1, 2014 in Denpasar, Bali, Indonesia. (Photo by Agung Parameswara/Getty Images)

“Just hanging out”. As full autumn hits the valley of Hallingdal in Norway, this bear chills out in a tree which seems to barely cover its weight. Photo location: Flå, Hallingdal, Norway. (Photo and caption by Jorgen Tharaldsen/National Geographic Photo Contest)

A thrill-seeking storm chaser captured the precise moment these giant lightning bolts lit up dark skies in a series of incredible storms. (Photo by Craig Eccles/Solent News & Photo Agency)

Michael O’Neill won a prize in animal portraits with fry of a peacock bass hovering around their mother for protection against predators in South Florida. (Photo by Michael Patrick O'Neill/2016 National Geographic Nature Photographer of the Year)