Tappa Ḥiṣār, Iranian archaeological site located near Dāmghān in northern Iran. Excavations made in 1931–32 by the University of Pennsylvania and in 1956 by the University of Tokyo demonstrated that the site was continuously inhabited from about 3900 to about 1900 bc. The long habitation sequence provided valuable evidence for the development of prehistoric pottery and metallurgy in that part of Iran. To the southwest of the main mound, a large Sāsānian palace was also uncovered.