Photo credit: Julian Herbert    After six days of riding, Ed Fernon of Australia and Barry Armitage of South Africa have crossed the finish line to become joint winners of the 2017 Mongol Derby. The Mongol Derby is down in the Guinness Book of World Records as the world’s longest and toughest horse race. This year, 41 men and women from around the world took on the challenge. They are racing 1,000km across Mongolia, recreating the ancient horse messenger system of Chinggis Khaan. They travel up to 160km a day, navigating themselves and changing horses every 40km. The riders either camp or