Climbing the signposted path from the Temple of Hercules, you pass a small ruined Byzantine church on the right, dating from the fifth or sixth century, which reused many of the columns from the nearby temple. The church formed part of a Byzantine town which probably covered much of the hill.
The remains of a large Umayyad mosque on the left indicate the beginning of the huge Umayyad Palace complex, which stretches over the northern part of the hill. Part of the palace was built over pre-existing Roman structures, and an entire colonnaded Roman street was incorporated into it. Built around 730, when Amman was a provincial capital, the complex probably combined the residential quarters of the governor of Amman with administrative offices. It was still in use during the Islamic Abbasid (750–969) and Fatimid (969–1179) periods, although much of the brand-new palace was never rebuilt following a devastating earthquake in 749.
Beyond the mosque you come to the impressive domed entrance hall, reached by crossing the first of four plazas. Built over an earlier Byzantine building (which is why it’s in the shape of a cross), the hall is decorated with stucco colonnettes and Persian-style geometric patterns, set off by foliage rosettes and a hound's-tooth zigzag. Much renovation has been carried out here in recent years, not all of it subtly – the new stucco around the interior walls deliberately clashes with the original work, and in 1998 a new dome was constructed above the building, though archeological controversy persists about whether there ever was a dome here in antiquity. To one side of the building are the remains of a small bathhouse, beside a large round cistern and what may have been an olive-pressing works.
Beyond the entrance hall is the second large plaza, from which the colonnaded street leads ahead. This was the heart of the administrative quarter, surrounded by nine separate office or residential buildings (of which only four have been excavated), each in the typical Umayyad style of a self-contained bayt – small rooms looking onto a central courtyard. The bayts were constructed within the pre-existing Roman enclosure, possibly a temple, whose exterior walls are still visible in places.
At the far end of the colonnaded street, a decorated doorway takes you through the Roman wall into the third plaza and the private residential quarters of the ruler of Amman. Rooms open from three sides, but the plaza is dominated by a huge iwan – an audience room open on one side – which leads through to a domed, cruciform throne room, or diwan. According to Umayyad protocol, the ruler stayed hidden behind a curtain during audiences; the tiny passageway between the iwan and the diwan could have served this purpose. To either side lie the residential bayts for the ruling household. At the back of the diwan, a doorway leads through to the fourth and final plaza – a private affair, looking north over the massive Roman retaining wall to the hills opposite.