Soldiers with the Afghan National Army (ANA) at an outpost in the Momand Valley on July 16, 2017 in Achin District, Afghanistan. The building was previously used as of a jail by the Islamic State of Iraq and Syria – Khorasan (ISIS-K) and was taken by Afghan Commandos nine days prior. Operations are currently underway to remove ISIS fighters from Nangarhar Province in Eastern Afghanistan. (Photo by Andrew Renneisen/Getty Images)

Urban photographer Roman Robroek spent five years scouring the continent for the grandest examples of forgotten architectural beauty. Here: Watch your step on this Polish spiral staircase. (Photo by Roman Robroek/South West News Service)

A Swiss police officer accompanies a migrant from Syria carrying her baby, upon her arrival at the railway station in the north-eastern Swiss town of Buchs September 1, 2015. (Photo by Arnd Wiegmann/Reuters)

The sign above the door of restaurant and hotel “Am Paulusbogen” is partially submerged in the flooded centre of the Bavarian town of Passau, about 200 km (124 miles) north-east of Munich June 3, 2013. (Photo by Michaela Rehle/Reuters)

Singer Ariana Grande performs during the 2014 MTV Europe Music Awards at the SSE Hydro Arena in Glasgow, on November 9, 2014. (Photo by Toby Melville/Reuters)

An applicant try-out during a stewardess recruiting interview for China Southern Airlines on October 12, 2006 in Beijing, China. Over 160 candidates have competed at the Beijing Region selection for a total of 15 berths in the next stage of recruitment. The China Southern Airlines launched a nationwide campaign to single out qualified stewardesses, the first of its kind to recruit stewardesses through TV shows. (Photo by China Photos/Getty Images)

A man holds a pigeon during the British Homing World show of the year at Blackpool's Winter Gardens in Blackpool, north west England on January 17, 2016. Homing pigeon fanciers from across Europe gathered to find the Supreme Show Champion with judges casting their eyes over hundreds of birds on show. The Royal Pigeon Racing Association organises the event and has Queen Elizabeth II, who keeps pigeons at Sandringham, as its patron. (Photo by Andrew Yates/Reuters)