Teppe Hasanlu or Tappeh Hassanlu (farsi: تپه حسنلو) is an archeological site of an ancient city located in northwest Iran (in the province of West Azarbaijan), a short distance south of Lake Urmia. The nature of its destruction at the end of the 9th century BCE essentially froze one layer of the city in time, providing researchers with extremely well-preserved buildings, artifacts, and skeletal remains from the victims and enemy combatants of the attack.
Hasanlu Tepe is the largest site in the Gadar River valley and dominates the small plain known as Solduz. The site consists of a 25m high central "citadel" mound, with massive fortifications and paved streets, surrounded by a low outer town, 8m above the surrounding plain. The entire site, once much larger but reduced in size by local agricultural and building activities, now measures about 600m across, with the citadel having a diameter of about 200 m.
The site was inhabited fairly continuously from the 6th millennium BCE to the 3rd century AD. It is famous for the "Gold Bowl" found by a team from the University of Pennsylvania led by Robert Dyson.
The site of Hasanlu was excavated in 10 seasons between 1956 and 1974 by a team from the University Museum, University of Pennsylvania and the Metropolitan Museum.
Originally, excavations in the Ushnu - Solduz Valley were intended to explore a series of stratified occupation levels in the area with the objective of reconstructing a regional cultural history from Neolithic times until Alexander the Great's conquest of iran beginning in 334BC, such that any conclusions would rely solely on material evidence from the region itself, independent of linguistic or literary evidence from adjoining regions.The unexpected discovery of the famous "Gold Bowl" at Hasanlu in 1958 led to the project shifting its focus to the Iron Age levels at this site, although several other sites in the region were also excavated in order to stay in line with the project's broader objective.
Although the Hasanlu Publications Project, initiated in 2007, has not yet published its official monograph-length final reports on the Iron Age levels from the excavations, two Excavation Reports and several Special Studies volumes have been completed publications.
The excavators have broken down the site’s occupation history into ten periods based on the nature of material finds in the different strata: the oldest, period X, stretches back to the Neolithic period, after which there was fairly continuous occupation until the early Iron Age (ca 1200-330 BC), followed by a hiatus before subsequent reoccupation; occupation finally ends in Iran’s medieval period (Hasanlu period I)