Marathon des Sables

Marathon des Sables, or MdS, (French for Marathon of the Sands, also known as Sahara Marathon) is a six-day, about 250 km (160 mi) ultramarathon, which is approximately the distance of six regular marathons. The longest single stage (2009) was 91 km (57 mi) long (2023 : 90.1km).

This multiday race is held every year in southern Morocco, in the Sahara Desert. Some runners may regard it as one of the toughest foot races on Earth.