The Mongol Derby is the longest and toughest horse race in the world.

The 1000km course recreates Chinggis Khaan's legendary empire-busting postal system. Riders change horses every 40km and stay with the local herders or camp under the stars.

Every year 40 professional, semi-professional and enthusiastic amateur riders compete for the derby crown.

To stand a chance of finishing riders must balance survival skills and horsemanship. They must endure the elements, semi-wild horses as well as unfamiliar food and terrain.

Completing the World's longest horse race is an achievement few can boast.