Tourists from the Middle East take pictures at Vrelo Bosne nature park in Ilidza near Sarajevo, Bosnia and Herzegovina, August 19, 2016. They discovered mountainous Bosnia, where half the population is Muslim, after the Arab Spring which destabilized many traditional holiday destinations such as Libya, Tunisia and Egypt. (Photo by Dado Ruvic/Reuters)

Passengers prepare to take part in the No Pants Subway Ride in Prague, Czech Republic, Sunday, January 8, 2017. The No Pants Subway Ride began in 2002 in New York as a stunt and has taken place in cities around the world since then. (Photo by Petr David Josek/AP Photo)

A woman directs traffic in the pouring rain in Pyongyang, North Korea on May 3, 2016. The city is preparing for the Workers' Party Congress starting on May 6th. It will be the first time since 1980 that the ruling party has convened. (Photo by Linda Davidson/The Washington Post)

A woman with a sign that reads in Portuguese “Being woman without Temer”, stands next to a police barricade during a protest against the gang rape of a 16-year-old girl in Sao Paulo, Brazil, Wednesday, June 1, 2016. In response to the assault, Brazil's interim President Michel Temer said that the country will set up a specialized group to fight violence against women. (Photo by Andre Penner/AP Photo)

These little grizzly bear cubs had fun making a real splash when their mum took them for a dip to learn how to fish. Kamchatka, Russia. (Photo by Marco Mattiussi/Solent News & Photo Agency)

Rihanna holds the pregnant belly of Spc. Ariel Evans during an event promoting her Rogue Man cologne at Ft. Belvoir Exchange on Wednesday, November 12, 2014 in Ft. Belvoir, Va. (Photo by Kevin Wolf/AP Photo)

This picture taken on September 3, 2014 shows a man taking pictures of floodwater released from the Three Gorges Dam, a gigantic hydropower project on the Yangtze river, in Yichang, central China's Hubei province, after heavy downpours in the upper reaches of the dam caused the highest flood peak of the year. Eleven people died and 27 others are missing after torrential rains battered southwest China's Chongqing, a municipality in the upper reaches of the Three Gorges Dam, causing thousands of houses to collapse, state media said. (Photo by AFP Photo/Stringer)

A girl plays with coloured chicks for sale prior to Easter celebrations in Byblos, Lebanon on March 22, 2015. (Photo by Jamal Saidi/Reuters)