This particular southeastern corner holds some of Morocco's greatest sights, principally the Sahara's picture-perfect undulating dunes near Merzouga, and the Tafilalt date palmery. It's best to avoid Er-Rachidia, a colonial town with little to offer, and even Erfoud, too, if possible, as it's
full of touts. Now that the road to Merzouga is completely paved, you can drive straight there without stopping. For traveling anywhere in the desert, ensure you have enough cash, charged batteries, bottled water, and toiletries to see you through for several days until you get to a major town.
You cannot fail to notice hundreds of holes along the roadside about 25 km before you reach Erfoud (from Tinejdad). The holes that look like giant molehills are actually an ancient irrigation system designed in Persia more than 3,000 years ago, which was first brought to Morocco by the Arabs in the 12th century. The wells are called khettara, and access water from the natural water table, channeling it through underground canals to different palm groves. On the left-hand side of the road as sand dunes begin to pile up—and 27 kms (17 mi) before reaching Erfoud (from the direction of Tinejdad)—look out for the ancient wells dating back to 11th century. Local guide, Said Ouatou, can be found in a Bedouin tent at the side of the road and will explain the science and history. Be careful if you have young children, the edges of the wells can crumble.
Morocco's longest river, the Draâ once flowed all the way to the Atlantic Ocean just north of Tan-Tan, some 960 km (600 mi) from its source above Ouarzazate. With the sole exception of a fluke flood in 1989—the only time in recent memory that the Draâ completed its course—the river now disappears in the Sahara southwest of M'Hamid, some 240 km (150 mi) from its headwaters. The Draâ Valley and its palmery continue nearly unbroken from Agdz through Zagora to M'Hamid, forming one of Morocco's most memorable tours.
As wild as you may have found certain parts of Morocco thus far, the trip down to the Sahara will seem more so, something like steady progress into a biblical epic. The plains south of Ouarzazate give way to 120 km (75 mi) of date palmeries and oases along the Draâ River, and between Agdz and Zagora more than two-dozen kasbahs and ksour line both sides of the river. The occasional market town offers a chance to mingle with the diverse peoples you'll see walking along the road in black shawls. Though most of the inhabitants are in fact Berbers, the Draâ Valley also contains Arab villages, small communities of Jews or the mellahs they once inhabited, and numerous Haratin, descendants of Sudanese slaves brought into Morocco along the caravan routes that facilitated salt, gold, and slave-trading until late in the 19th century.
After Zagora and Tamegroute, the road narrows as the Tinfou Dunes rise to the east and, farther south, a maze of jeep tracks leads out to Erg L'Houdi (Dune of the Jew). Finally, in M'Hamid el Ghizlane (Plain of the Gazelles), with sand drifting across the road and the Draâ long since gone underground, there is a definite sense of closure, the end of the road.
Morocco without the Sahara is like Switzerland without the Alps, and a trip to the desert is fundamental to an understanding of the country. After you've seen the Atlas Mountains, followed by gorges, oases, palmeries, and kasbahs, a trip down to the desert may seem a long way to go to reach nothing, and some Moroccans and travelers will warn you against it. Don't listen to them. The void you encounter in the Sahara will remind you why prophets and sages sought the desert to purge and purify themselves.
Once, the caravan routes from the Sudan, Timbuktu, and Niger to Marrakesh and Fez passed through Morocco's Great Oasis Valleys and were fundamental to the region's history. From the Draâ Valley came the Saadian royal dynasty that ruled from the mid-12th to mid-17th century, and from the Ziz Valley and the Tafilalt oasis rose the Alaouite dynasty, which relieved the Saadians in 1669 and which still rules (in the person of King Mohammed VI) in 21st-century Morocco.
A trip through the oasis valleys doesn't just get you sand for your trouble. The asphalt might end and the desert begin at Merzouga and M'Hamid, but in between are the oases flanked by the High Atlas Mountains and the Todra and Dadès gorges—sister grand canyons separating the High Atlas from the Djebel Sarhro Massif.
Doing the entire circuit in the Great Oasis Valleys is a serious undertaking, and you might easily miss the best parts for all the whirlwind traveling. Walking in the Dadès or Todra gorge could easily take three days, and you should stay in at least one for a few days. Whichever gateway you choose, you should allot two days and a night at the very minimum for a trip to the desert. Unless you have oodles of time you'll have to choose between the dunes of Erg Chebbi at Merzouga and Erg Chegaga beyond M'Hamid, which are separated by 450 km (279 mi) of long, hard driving.
The drive through Morocco's smaller versions of the Grand Canyon is stunning, and the area merits several days' exploration. The Dadès Gorge is frequented more by independent travelers than tours, while the Todra is much more about mass-organized tourism. So many buses stop at the most beautiful point that you almost forget it's supposed to be beautiful. If you avoid lunchtime (when all the tour buses disgorge), however, and venture on, there are some great walks and lovely spots where you can feel much more alone.