As the sun sets on the Malecon in Havana on Friday January 23, 2015, Surenis Angulo de la Paz, 24, center, dances as group of locals play music around her. Behind her is Fidel Lopez, 55. (Photo by Sarah L. Voisin/The Washington Post)

A worker pauses for a sandwich, resting on a girder during the construction of a skycraper. (Photo by Hulton Archive/Getty Images). Circa 1930

A man prays to mourn victims of the March 11, 2011, earthquake and tsunami in front of a ship brought ashore by the disaster in Kesennuma, Miyagi Prefecture, Japan. (Photo by Kyodo via Reuters)

A Muslim boy prepares plates of food for an Iftar (breaking of fast) meal inside a mosque during the holy month of Ramadan in Ahmedabad, India, June 28, 2015. (Photo by Amit Dave/Reuters)

Timbuktu: A UN peacekeeper from Burkina Faso stands guard at the Djinguereber mosque, built in the 14th century, during a visit by a UN delegation on election day in Timbuktu, Mali, July 28, 2013. (Photo by Joe Penney/Reuters)

Children in Hiroshima, Japan, wearing masks to combat the odour of death after the city was destroyed by the first atom bomb. (Photo by Keystone/Getty Images). 1945

Wakhi nomad women milk yaks in Wakhan, Afghanistan. About 12,000 villagers live at an altitude of 4,500 metres in the harsh, desolate terrain. The Wakhi people live a simple, relaxed life with their livestock. (Photo by Eric Lafforgue/Barcroft Images)

People at a Czech Stop look at a cloud of smoke rising from the explosion in West, Texas, April 17, 2013. (Photo by Andy Bartee via Dallas Morning News/MCT)