It was built by using unshaped boulders to about 20 ft high. Each stone is broad and thick and some of them are about 10 ft high and about 4 ft long. It is believed that it was built before the time of usage of metal tools.[2]Arthur Maurice Hocart noted that cyclopean style stone walls were used for the fortress, and square hammered stones were used for the ramparts of the citadel. However, his note suggests metal (iron) tools were used for construction. Excavations work in this areas found a few stone forges, which proved Hocart's claim on the usage of metal tools.[3]