The fortress extended west as far as the seashore. The Italian excavators concluded that the conversion to a fortress occurred in the sixth century under the Emperor Justinian. In one of our rescue excavations, however, we found the fortress wall had incorporated earlier walls whose foundation-trenches runs over fill that led into a drain channel of a Byzantine latrine. The fill included many pottery fragments from the sixth-seventh century. Therefore these walls must be dated later than suggested by the Italian excavators. Since Islamic records mention the fortification of Caesarea after the 640 C.E. Arab conquest, we suggest that the fortress was the seat of the Arab/Islamic garrison. The architecture of the fortress fortification—a solid wall with semi-circular towers—is appropriate for early Islamic fortifications rather than Persian or Byzantine fortifications.