Qastal is one of the oldest of the Umayyad palaces, as well as one of the best preserved. The remains at Qastal include a wide variety of sites such as the central palace, baths, a reservoir, a mosque, small houses, a cemetery—the oldest Muslim graveyard in Jordan—and a dam. 

The central palace was decorated with stone carvings, and twelve semi-circular turrets buttressed and guarded the walls. The courtyard of the palace housed a central water tank. North of the central palace are the remains of the mosque. Interestingly, it is not oriented precisely eastwards facing Mecca.

One kilometer east of the main complex are the remains of a stone dam, constructed to retain rainwater. Formed from the quarry which supplied stone for Qastal’s palace, the dam had a capacity of around two million cubic meters. Qastal was probably built in the early Islamic era by the Umayyad Caliph ‘Abd al-Malik ibn Marwan, who is known primarily for building the magnificent Dome of the Rock Mosque in Jerusalem.

The palace of Qastal is 100 meters west of the Desert Highway near the town of Qastal, 25 kilometers south of Amman.