The area around Dar Tichitt in southern Mauritania has been the subject of much archaeological attention, revealing successive layers of settlement near what still were small lakes as late as 1200 BCE. At this time people there built circular compounds, 60-100 feet in diameter, near the beaches of the lakes.
The Empire of Ghana, was centered in what is the modern country of Mali, where complex societies existed as far back as 1,500 B.C. The domestication of the camel, hundreds of years before Arabs, facilitated trade over vast distances of gold, ivory and salt. Merchants paid taxes to the king, making him on of the wealthiest rulers in the world.