Towering above downtown Amman, the site of the earliest fortifications is now subject to numerous excavations which have revealed remains from the Middle Bronze Age (2nd mill. BC) and the Iron Age (8th century BC), as well as from Hellenistic (2nd century BC) and late Roman to Arab Islamic Ages.
In the Citadel, beside the Jordan Archaeological Museum, three important structures can be viewed:
The Byzantine Church
The remains of a small Byzantine Basilica. Corinthian columns mark the site, which is thought to date from the 6th or 7th century AD.
Temple of Hercules
About 100 meters south of the church is what is thought to have been the Temple of Hercules, today also known as the Great Temple of Amman. The temple was built in the reign of the Emperor Marcus Aurelius (161-180 AD).
Umayyad Palace Complex
The most impressive building of the Citadel is known simply as Al-Qaser (the Palace), which dates back to the Islamic Umayyad period around 720 AD. Its exact function is unknown, but the building includes a monumental gateway, cruciform audience hall and four vaulted chambers. A colonnaded street runs through the complex and to the north and east, ruins of the palace grounds are visible.