The Ultra-Trail du Mont-Blanc (also referred to as UTMB) is
a mountain ultramarathon. It takes place once a year in the Alps, across
France, Italy and Switzerland. The distance is approximately 166 km, with a
total elevation gain of around 9,400 m. It is widely regarded as the most
difficult foot race in Europe. While the best runners complete the loop in
slightly more than 20 hours, most runners take 30 to 45 hours to reach the
finish line.
Official UTMB video
