The Diyala River valley is another region for which the ED period is relatively well-known. Along with neighboring areas, this region was home to Scarlet Ware—a type of painted pottery characterized by geometric motifs representing natural and anthropomorphic figures. In the Jebel Hamrin, fortresses such as Tell Gubba and Tell Maddhur were constructed. It has been suggested that these sites were established to protect the main trade route from the Mesopotamian lowlands to the Iranian plateau. The main Early Dynastic sites in this region are Tell Asmar and Khafajah. Their political structure is unknown, but these sites were culturally influenced by the larger cities in the Mesopotamian lowland.