The Ziz River leaves its craggy gorges behind at the city of Er Rachidia and continues its southward journey for another 100km (62 miles) along the Ziz Valley to the Moroccan pre-Sahara (hammada). Along the way, the largely hidden river feeds a string of oases and brings life to what would otherwise be dirt and stone. Dotted along its greenbelt are groups of kasbahs, or ksour, built to protect families in what was, until the 1930s, a largely lawless land. Some of the Ziz ksour have been abandoned for modern housing (the need for walled security no longer exists), but many are still standing and can be viewed from various roadside viewpoints alongside the valley.

At the valley's southern extreme is an area known as the Tafilalt, sometimes spelled Tafilalet or Tafilet. From the 8th to the 10th centuries, this was an independent kingdom, wealthy from its trading role on the ancient Saharan caravan routes traveling through here between west and northeast Africa. Filalis, the people of the Tafilalt, have kept this independent streak through the centuries. The Alaouites, still sitting on the throne today through King Mohammed VI, originated here with the desert sultan Moulay Rachid, and the French met with fierce resistance in the Tafilalt for almost 20 years before finally succeeding in their "pacification program" of the area.

The Oued Ziz completes its journey under the Erg Chebbi, a sweeping sea of sand 30km (19 miles) long and 7km (4 1/3 miles) wide, isolated from the Sahara ocean by the Moroccan hammada. Ultimately, this is the destination that makes the hot journey worthwhile. The combination of 150m-high (490-ft.) dunes, sometimes gold, sometimes rust red, with indigo-robed nomads, oases of date palms, and trains of camels is the quintessential desert landscape.