The Goebekly-Depe fortress in Margiana in the context of Iranian fortification development

The fortress of Goebekly-depe on the northern border of the Merv oasis, 32 km to the North-West of the Old Merv hillforts is of special significance for the history of Iranian fortification. It was built in the Parthian period, supposedly, in the first century AD, and was repeatedly rebuilt during the Early Sasanian period in the 3rd and 4th centuries. After the mid-fourth century the fortress was abandoned. The time of its active use is dated on the basis of Parthian and Sasanian coin finds, the latest are copper coins of Shapur II (309-379). Judging by the finds of clay bullae used to seal packs of goods, in the Parthian period the fortress functioned as a customs post. When the fortress was rebuilt during the Sasanian period the lower level rooms were filled with mudbricks and so turned into a monolithic platforms. These changes should be regarded in the context of development of Iranian fortification in genetrel, relying on similar constructions in Gurgan, Pars, Khorasan and Mesopotamia.