The route
From Marrakech, the road climbs through the High Atlas to the Tizi n'Tichka pass, then descends to Aït Benhaddou and Ouarzazate. It continues east along the "road of a thousand kasbahs" through the Dades Valley and Tinghir, with side trips into the Dades and Todra gorges, before crossing the desert to Rissani and Merzouga.
Tours
The most popular option is a 3-day tour: day one to the Dades Valley, day two through the Todra Gorge to Merzouga and a camel ride to a desert camp, and day three back to Marrakech or on to Fes. Longer tours allow more time at each stop.
Bus or self-drive
Supratours runs buses from Marrakech to Merzouga, a long journey of most of a day. Driving yourself gives the most freedom; allow at least two days each way to enjoy the stops.