Marathon des Sables, or MdS, (French for Marathon of the Sands, also known as Sahara Marathon) is a six-day, 251 km (156 mi) ultramarathon, which is approximately the distance of six regular marathons. The longest single stage (2009) is 91 km (57 mi) long.
This multiday race is held every year in southern Morocco, in the Sahara Desert. It has been regarded as the toughest foot race on Earth. The first event of the Marathon started in 1986.
