In this July 23, 2013 photo, sand fills an abandoned house in Kolmanskop, Namibia. Kolmanskop, was a diamond mining town south of Namibia, build in 1908 and deserted in 1956. SInce then, the desert slowly reclaims its territory, with sand invading the buildings where 350 German colonists and more than 800 local workers lived during its hay-days of the 1920s. (Photo by Jerome Delay/AP Photo)

Bosnian worker Sefik Salihovic drives a steam engine in the Bosnian town of Banovici, 140 kms (86.9 miles) north of Sarajevo, on Monday, November 24, 2014. Every day, steam engines over 60 years old, defy their age and still pull wagons of coal from Banovici's coal mine to clients in nearby towns. But in the summer some of them turn into the only tourist attraction this impoverished north Bosnian town has to offer. (Photo by Amel Emric/AP Photo)

General view of the monument to memory of soldiers who liberated the city of Knin – in Knin, Croatia on November 10, 2014. Across the former Yugoslavia stand giant monuments to a state that no longer exists, once visited and celebrated during public holidays such as Republic Day on November 29, marking the creation of socialist Yugoslavia. Many are now neglected or ignored, aging symbols of a joint state forged during World War Two but torn apart by nationalism half a century later. Republic Day is no longer marked in any of the seven independent states that emerged from its ashes. (Photo by Antonio Bronic/Reuters)

Models clad in costumes of video game charactors pose at a game booth during the Tokyo Game Show 2016 in Chiba, suburb of Tokyo, on September 15, 2016. Sony took centre stage at the annual four-day event, with its virtual reality headset ready to hit store shelves for the Christmas shopping season. (Photo by Toru Yamanaka/AFP Photo)

A woman smokes a cigar as she reads the newspaper in a street of Havana, on November 26, 2016, the day after Cuban revolutionary leader Fidel Castro died aged 90. One of the world's longest-serving rulers and modern history's most singular characters, Castro defied 11 US administrations and hundreds of assassination attempts. (Photo by Yamil Lage/AFP Photo)

A Pakistani devotee dances to celebrate the three-day annual festival to pay tribute to the famous saint Al-Sheikh Ali Bin Usman Al-Hajveri known as Data Ganjbaksh at outside his shrine in Lahore, Pakistan, Sunday, November 20, 2016. Thousands of people traveled from all over Pakistan to attend the celebrations. (Photo by K.M. Chaudary/AP Photo)

Syrian government troops patrol the newly captured al- Sakhour neighbourhood in the eastern part of the northern city of Aleppo on December 7, 2016 Rebels in Aleppo called for a five- day truce and the evacuation of civilians Wednesday after losing more than three quarters of their territory including the Old City to a Syrian army offensive. (Photo by George Ourfalian/AFP Photo)

A “creuseur”, or digger, a plastic lantern on his head, readies to enter a copper and cobalt mine in Kawama, Democratic Republic of Congo on June 8, 2016. Cobalt is used in the batteries for electric cars and mobile phones. Working conditions are dangerous, often with no safety equipment or structural support for the tunnels. The diggers say they are paid on average US$2-3/day. (Photo by Michael Robinson Chavez/The Washington Post)