From the “Paradise Revisited” story in the November 2013 issue of National Geographic magazine, this image is a beautiful vision of father and son fishermen as they move through the multicolored coral gardens of Kembe Bay, Papua New Guinea, in a traditional outrigger canoe. (Photo by David Doubilet/National Geographic Creative)

An Iraqi military vehicle passes displaced Iraqi boys returning to their homes in West Mosul's Oreibi neighbourhood after government forces retook control of the area from the Islamic State (IS) group during the ongoing offensive against the jihadists on May 21, 2017. (Photo by Ahmad Al-Rubaye/AFP Photo)

People walk along the Neva River at sunset in St.Petersburg, Russia, Tuesday, December 6, 2016. The temperature in St.Petersburg is –9C ( 15.8 °F). (Photo by Dmitri Lovetsky/AP Photo)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

Israeli soldiers of the Search and Rescue brigade take part in a training session in Ben Shemen forest, near the city of Modi'in May 23, 2016. (Photo by Amir Cohen/Reuters)

An elderly man uses a fan to shade himself from the sun as he walks in a public park in Beijing, Tuesday, June 7, 2016. Thursday marks the Duanwu Festival, a public holiday in China celebrated with outdoor activities including dragon boat races. (Photo by Mark Schiefelbein/AP Photo)

A man carries his wife over an obstacle while competing in the Wife Carrying Championship to mark City Day in Krasnoyarsk, Siberia, Russia, June 25, 2016. (Photo by Ilya Naymushin/Reuters)

People take pictures of deer in the Phoenix Park in Dublin, Ireland December 5, 2016. (Photo by Clodagh Kilcoyne/Reuters)