Morocco's Saharan sand dunes are the stuff of legend, and sitting on a camel as the sun sets over the golden sands is one of life's most sublime experiences. The dunes here are called ergs, "islands of sand" in Arabic, and they radiate beauty and a rare sense of tranquility. Today's camel trekking routes through the ergs follow the 9th century trans-Saharan caravan trade routes which carried salt, gold, slaves and spices from sub-Saharan Africa to the Mediterranean ports and the Middle East. The present day village of Rissani was the main oasis and stopping point on the caravans' journey. This is where the Ziz River is finally overwhelmed by sand and stone and where caravans used to unload some of their gold and slaves, and the travelers and camels could get water and a humble meal of cous cous.