[CondorFlight]

“including two towers and strong exterior walls”

probably necessary because of the advent of muslim raiders.

[SunkenCiv]

It may have been; it may have been added by those very same raiders when they took over. For that matter, it may have been because of piratical raids by their very own neighbors in the Aegean.

[marktwain]

“including two towers and strong exterior walls” probably necessary because of the advent of muslim raiders.

Exactly my thought.