Among the Western Sudan's earliest forms of artistic expression are depictions of couples in terracotta and cast-alloy copper from Mali's Inland Niger Delta. These works have been related to the ancient urban center of Djenne-Jeno, three kilometers southwest of the contemporary city of Djenne. Archaeologists have determined that the site was settled about 250 B.C. and that it was continuously occupied by an ethnically diverse population for more than a millennium before its abandonment about A.D. 1500. It has been suggested that Djenne-Jeno's decline may have been related to the arrival of Islam and that a new urban settlement purged of traditional religious practices was established at Djenne once the community's leadership converted.