A workman takes a siesta on a girder during the building of Radio City, the city of New York spread out below. (Photo by General Photographic Agency/Getty Images). Circa 1933

“Catch of the Decade”. Can you guess what happened next? Photo location: Katmai National Park, Alaska, USA. (Photo and caption by Aaron Baggenstos/National Geographic Photo Contest)

Ranger trainees and trainee dogs simulate an ambush against rhino poachers at the Paramount Group Anti-Poaching training and K9 (canine) academy on November 26, 2014 in Magaliesberg, South Africa. One of the largest of its kind in Africa, the Academy will address the ever increasing need for training of Conservation Officers in anti poaching activities, wildlife contraband detection, specialist K9 solutions and Ranger K9 handler training – all of which have proven success rates in combatting and apprehending poachers and their activities. (Photo by Gianluigi Guercia/AFP Photo)

A participant of the sled dogs race in action with the dogs in Stroehen (Lower Saxony), Germany, 18 October 2015. It is the first round of the North German Championship. (Photo by Peter Steffen/EPA)

NYC morning fog. Wednsday, January 15, 2014, morning dense fog creates spectacular views over the East river of lower Manhattan, Brooklyn and Manhattan bridges as New Yorkers and tourist admire the scenery. View from Brooklyn Bridge Park in DUMBO Brooklyn. (Photo by Paul Martinka/New York Post)

Museum assistant and former Soviet soldier, Sheikh Abdullah looks at a display in the Manzar-e Jahad, or Jihad Museum, which depicts the Soviet invasion of 1979 and the Afghan resistance, in Herat, on February 15, 2014. Sheikh Abdullah, who was a Soviet intelligence officer by the name of Khakimov Bakhrodin, was captured after being injured in battle with the Mujahideen. Abdullah stayed with his captors, converted to Islam and was renamed Abdullah. He never returned to his former homeland and now works at the Jihad Museum. (Photo by Aref Karimi/AFP Photo via The Atlantic)

A Palestinian throws snow at his wife during a snow storm in West Bank old city of Hebron, January 26, 2016. (Photo by Mussa Qawasma/Reuters)

A man holds a metal bar as a weapon during a training day for former soldiers and volunteers train in a makeshift camp in the outskirts of Port-au-Prince, Haiti, October 28, 2015. Haiti disbanded its abusive armed forces two decades ago but uniformed veterans and young recruits are resurfacing to add another destabilising factor to the volatile Caribbean nation already dealing with a political vacuum. (Photo by Andres Martinez Casares/Reuters)