The UltraTrail du Mont Blanc (UTMB) is a popular long-distance running race, which follows the challenging route of the Tour du Mont Blanc (a long-distance walking trail) through France, Italy and Switzerland.
This ultramarathon is one of the most iconic trail races in the world, winding 166km around the Mont Blanc massif, rising over Alpine passes on its way from Chamonix in France to Switzerland, down into Italy and back to the finish line in Chamonix.