Located 40km east of Amman in an arid zone, about 14-19km north east of Muwaqqar and 21km north west of Kharraneh, the Qasr complex settlement was a caravan station on the route between Amman/Philadelphia and Wadi Sirhan. The main Qasr has 13 rooms with a central courtyard and an eastern entrance. The oldest part of the site is the Qasr itself in the East, and seems to have been occupied since the fourth century AD, as part of the Roman guard posts in the Arabian Desert. The complex was also used during the Umayyad times, for the same purpose, while earlier Byzantine settlements are also evident. The ruins of this latter large complex (2km2) settlement was once a grand site in the desert steppe, which probably served as a caravan station in Umayyad times. The structure designated as ‘caravanserai’, with a large courtyard, is the largest of the total of four square complexes in Mushash.
The settlement complex has a large number of hydraulic systems in the form of reservoirs, cisterns and dams. It has several, spatially separate units of various functions. According to the research done by the Deutsche Archaeological Institute in Amman, the Qasr, there has a large hydraulic system, with many cistern reservoirs and dams serving the Qasr and a bath. The large reservoir located in the west, at a distance from the residential and functional buildings, was possibly used for watering animals.
There are two Qasrs; the West Qasr and East Qasr. The Western one is a small square building located from the core of the complex and embraces an area of some nine hectares. By comparison to the neighbouring Qusayr Amra, its bath is of rather modest design. The settlement section to the west of the central area with smaller, multi-roomed houses can be interpreted as a simple residential area, while the buildings northeast of the central area, differing noticeably from the western houses in size and internal division, might have served as representational structures. The medieval Arab historian el-Maqdisi mentioned that the Qasr was on one of the three routes from Amman to the Hijaz in western Arabia and was used by the Umayyad postal service.