A house built on a rock on the river Drina is seen near the western Serbian town of Bajina Basta, about 160km (99 miles) from the capital Belgrade May 22, 2013. The house was built in 1968 by a group of young men who decided that the rock on the river was an ideal place for a tiny shelter, according to the house's co-owner, who was among those involved in its construction. (Photo by Marko Djurica/Reuters)

A soldier helps another with her ear protection at the Terningmoen Camp in Elverum, Norway on March 23, 2017. Soldiers demonstrate their skills and tactics during a contract drill as they train to become part of the world's first all-female special forces unit, the Jegertroppen or “hunter troops”. (Photo by Carolina Reid/NBC News)

Bulgarian Muslims Azim Liumankov and his bride Fikrie Bindzheva pose in front of their house during their wedding ceremony in the village of Ribnovo, in the Rhodope Mountains, February 15, 2015. The remote mountain village of Ribnovo in southwest Bulgaria has kept its traditional winter marriage ceremony alive despite decades of Communist persecution, followed by poverty that forced many men to seek work abroad. (Photo by Stoyan Nenov/Reuters)

Inmates sleep on the steps of a ladder inside the Quezon City jail at night in Manila in this picture taken on July 21, 2016. There are 3,800 inmates at the jail, which was built six decades ago to house 800, and they engage in a relentless contest for space. Men take turns to sleep on the cracked cement floor of an open-air basketball court, the steps of staircases, underneath beds and hammocks made out of old blankets. (Photo by Noel Celis/AFP Photo)

Online hostess Xianggong (L) and other hostesses check their pictures as they gather around the photographer while taking part in a football-themed photoshoot at a photography studio in Beijing March 4, 2015. In China's online hostessing world, men find virtual company and the women can find riches. Xianggong is one of more than 10,000 hostesses on the internet site bobo.com, a live broadcasting web platform where anyone can record themselves singing, playing piano, dancing or just chatting. (Photo by Jason Lee/Reuters)

Iraq's second largest city, Mosul, is locked under the rule of extremists from the Islamic State group trying to purge it of everything they see as contradicting their stark vision of Islam. A trove of photographs now housed at the Library of Congress offers a glimpse of a different Mosul – before wars, insurgency, sectarian strife and now radicals' rule. The scenes were taken in the autumn of 1932 by staff from the American Colony Photo Department during a visit to Iraq at the end of the British mandate. (Photo by AP Photo)

This November 11, 2014 aerial photo, shows a deforested area dotted with blue tarps, marking the area where miners reside, and craters filled with water, caused by illegal gold mining activities, in La Pampa, in Peru's Madre de Dios region. Less than a month before Peru plays host to global climate talks, the government sent a battalion of police into southeastern jungles to dismantle illegal gold-mining mining camps. Peru's anti-illegal mining czar, retired army Gen. Augusto Soto, marched the men to the wasteland known as La Pampa, where 50,000 hectares of rainforest have been obliterated in the past six years. (Photo by Rodrigo Abd/AP Photo)

Performers wearing 19th century French military uniforms fire their weapons as they attack Allied forces during a reenactment of the Battle of the Nations, in a field in the village of Markkleeberg near Leipzig October 20, 2013. The east German city of Leipzig commemorated the 200th anniversary of the largest battle of the Napoleonic Wars on Sunday by reenacting the Battle of the Nations, with 6,000 military-historic association enthusiasts from all over Europe. The decisive encounter in which tens of thousands of soldiers were killed, took place from October 17-19, 1813, just outside of Leipzig. At the height of the hostilities Napoleon fielded more than 200,000 men against an Allied force of some 360,000 soldiers which included troops from Russia, Austria, Prussia and Sweden. (Photo by Fabrizio Bensch/Reuters)