The strategic significance of the castle is that it lies in the middle of the Azraqoasis, the only permanent source of fresh water in approximately 12,000 square kilometres (4,600 sq mi) of desert. Several civilizations are known to have occupied the site for its strategic value in this remote and arid desert area.
The area was inhabited by the Nabataean people and around 200 CE fell under the control of the Romans. The Romans built a stone structure using the local basalt stone that formed a basis for later constructions on the site, a structure that was equally used by the Byzantine andUmayyad empires.
Qasr al-Azraq underwent its final major stage of building in 1237 CE, when 'Izz ad-Din Aybak, an emir of the Ayyubids, redesigned and fortified it. The fortress in its present form dates to this period.
In the 16th century the Ottoman Turks stationed a garrison there, and T. E. Lawrence (Lawrence of Arabia) made the fortress his desert headquarters during the winter of 1917, during the Great Arab Revolt against the Ottoman Empire. His office was in the chamber above the entrance gatehouse. It had an additional advantage in modern warfare: the flat nearby desert was an ideal place to build an airfield.
Today
Qasr al-Azraq is often included on day trips from Amman to the desert castles, along with Qasr Kharana and Qasr Amra, both east of the capital and reached via Highway 40. Admission is JD 2. Visitors can explore most of the castle, both upstairs and downstairs, except for some sections closed off while the rock is shored up. There is little interpretive material at the moment
