Complex sentence: Nor are there any other vestiges of antiquity still remaining at Enna: they were probably destroyed by the Saracens, who erected the castle and several other of the most prominent buildings of the modern city.
Split into simpler sentences: Nor are there any other vestiges of antiquity still remaining at Enna. They were probably destroyed by the Saracens, who erected the castle and several other of the most prominent buildings of the modern city.