A Polisario fighter sits on a rock at a forward base on the outskirts of Tifariti, Western Sahara, September 9, 2016. At a rocky outpost in Western Sahara, a new generation of soldiers who have never known war are mobilising as tensions resurface in one of Africa's oldest disputes after a quarter century of uneasy peace. (Photo by Zohra Bensemra/Reuters)

The barren landscapes of the south-western US provided inspiration for photographer David Clapp. He visited Nevada, New Mexico, Utah and Arizona as part of his project on other-worldy locations, with surreal results. Here: An infrared image at dusk of strange clay rock formations in Ah-Shi-Sle-Pah Wilderness in Farmington, New Mexico. (Photo by David Clapp/Barcroft Images)

A Palestinian man walks down snow-covered stairs after Friday prayers near the Dome of the Rock on the compound known to Muslims as Noble Sanctuary and to Jews as Temple Mount, in Jerusalem's Old City February 20, 2015. Snow covered Jerusalem and mountainous areas of Israel early Friday morning and the education ministry closed schools for the day. (Photo by Ammar Awad/Reuters)

A North Korean soldier throws a stone towards a photographer on the banks of the Yalu River in the North Korean town of Sinuiju, opposite the Chinese border city of Dandong October 21, 2006 in Sinuiju, Democratic People's Republic of Korea. (Photo by Cancan Chu/Getty Images)

Battle-weary American troops withdraw from Yong San in Korea. (Photo by Keystone/Getty Images). 1950

American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)