Tourists ice skate at night on the Eiffel Tower's skating rink in Paris December 9, 2014. The skating rink, located on the first level of the Eiffel Tower, opens to the public as part of the Christmas holiday season. (Photo by Charles Platiau/Reuters)

A mahout splashes water on his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India, May 20, 2015. (Photo by Amit Dave/Reuters)

People walk past the Sleepwalker, a sculpture along the High Line in New York, US on May 10, 2016. The hyperrealistic work by Brooklyn artist Tony Matelli is part of the linear park’s Wanderlust exhibition. (Photo by Xinhua/Barcroft Images)

This photo taken on August 7, 2016 shows mahjong enthusiasts playing mahjong under water in a swimming pool at a diving club in the Chinese city of Chongqing. Only participants with proper diving certification were allowed to take part in the underwater competition. (Photo by AFP Photo/Stringer)

Firefighting teams try to extinguish an oil fire November 27, 2016 as smoke billows from one of the remaining oil wells set ablaze by ISIL in their retreat from Qayyarah at the start of the Mosul offensive which began more than a month prior. (Photo by Byron Smith/ZUMA Wire/Rex Features/Shutterstock)

A reveller takes part in an annual block party known as “Cordao de Prata Preta”, one of the many carnival parties to take place in the neighbourhoods of Rio de Janeiro, February 6, 2016. (Photo by Pilar Olivares/Reuters)

In this photo taken on July 19, 2014, a man looks at an excavation as an A.R.M.H., Association for the Recovery of Historical Memory, volunteer digs on the search for the body of Perfecto de Dios, in a hidden grave in Chaherrero, Spain. Across Spain, volunteer teams of archeologists, anthropologists and forensic scientists head out every year on expeditions to dig for suspected mass graves – a legacy of Spain's fascist past during the time of General Francisco Franco. (Photo by Daniel Ochoa de Olza/AP Photo)

Pakistani laborers transport the front portion of a vehicle using a handcart at a road in Peshawar, Pakistan, Monday, August 3, 2015. (Photo by Mohammad Sajjad/AP Photo)