The Inner Niger Delta, from Djenne at the southern end to Timbuctu at the northern end .
This is a traditional natural geographic region of grasslands flooded by the Niger river, which possibly served as the location of the first agriculture in West Africa (West African rice domesticated 50-400 CE).
Mostly an urban no-mansland, its importance has been as a grocery store for cities, dry-season pastureland for herders, and a crossroads in West African trade network. The main urban centers, at the polar extremes of the NGA, emerged in the 13th century CE (an earlier large site at Jenne-jeno, a short distance from Djenne, was first settled from 250 BCE). The cities and polities of Ghana and Gao, the bases of influential but relatively low complexity polities, arose to the east and west outside of the NGA and staked an interest in the region from about 700 CE.
Likewise, the Mali Empire and Songhai Empire, from the 13th and 16th centuries, the largest and most powerful polities to control this region, had their capital centers outside the NGA zone to the east and west.