Qasr al Hallabat, Desert palace in Zarqa Governorate, Jordan

Qasr al-Hallabat is a square Umayyad palace with a 44-metre side and square corner towers projecting 2.5 metres beyond the walls. It is built of dressed limestone and basalt, some blocks bearing Latin inscriptions. Rooms and halls surround an open courtyard with a rainwater cistern; the site also includes a small mosque and a bathhouse.

A Roman fort was built in the 2nd–3rd century AD to guard the Via Nova Traiana, the road linking Damascus to Aila. A Latin inscription records a new fort dated to 212–213 under Emperor Caracalla, and another of 529 points to Byzantine repairs. In the 6th century the fort was ceded to the Ghassanids, who built a monastery. Caliph Hisham ibn Abd al-Malik later demolished and rebuilt it as an Umayyad desert complex.

The installation formed an important administrative outpost along the Roman frontier defense system and later served as a symbol of Umayyad caliphal authority. The preserved bathhouse with its mosaics demonstrates the social importance of public bathing rituals in the early medieval Near East. Religious structures within the compound reflect the transformation of the region during the Islamic expansion of the seventh century.

The site lies 25 km northeast of Zarqa, north of the paved road linking Zarqa to the Azraq oasis. The ground is uneven, with loose stones around the walls and towers. The mosque stands about 14 m southeast of the main palace, and the bathhouse of Hammam as-Sarah lies east of the castle. There is little shade, so visit in the morning.

In 2007, excavating a palace cistern, archaeologists found the remains of six people dated to 772–895 AD, after the Umayyad period. Five had suffered serious blows to the skull around the time of death, and three also bore cuts on their limbs. The bodies had been deliberately placed in the cistern, perhaps to hide the killings or send a message.