A photo taken on July 22, 2017 shows beach- goers dancing at the West Sea Barrage beach outside the coastal city of Nampo, southwest of Pyongyang. The West Sea Barrage beach features as a stopping point for foreign tourists, and is a destination for North Korean work groups from the neighbouring area. The beach lies at the end of an eight- kilometre- long barrage that separates the sea from the Taedong River, which runs through Pyongyang. (Photo by Ed Jones/AFP Photo)

France's Christian Lavieille and co-pilot Jean-Michel Polato compete with their Proto Dessoude during the first stage of the Dakar Rally 2013 from Lima to Pisco January 5, 2013. (Photo by Jacky Naegelen/Reuters)

The northern lights, or aurora borealis, appear in the sky over the Bamburgh lighthouse at Stag Rock in Northumberland, England on September 28, 2016. (Photo by Owen Humphreys/PA Wire via ZUMA Press)

Members of the staff wait for the start of the maiden press conference for China's all-girl “boyband” FFC-Acrush in Beijing, China April 28, 2017. Picture taken April, 28, 2017. (Photo by Damir Sagolj/Reuters)

A man carries an injured child amidst rubble near a burning vehicle in a site damaged from what activists said was shelling by forces loyal to Syria's President Bashar al-Assad in the town of Douma, eastern Ghouta in Damascus, Syria December 30, 2015. (Photo by Bassam Khabieh/Reuters)

Mark Dill and Brit Thacker practice acro-yoga as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. August 29, 2016. (Photo by Jim Urquhart/Reuters)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

Blankets cover the bodies of a woman (right) and a man (left background) hit by a northbound Penn Central train (background) as they waited with a crowd at Pennsylvania Railroad station in Elizabeth, N.J. on June 8, 1968 to view the southbound train carrying the body of Sen. Robert F. Kennedy to Washington. The woman was identified as Mrs. Antoinette Severini, 54, and the man, John Curia (age unavailable), both of Elizabeth. (Photo by AP Photo)