The imposing castle at Aci Castello was constructed out of volcanic rock on top of La Rocca by the Normans starting in the late 11th century. Prior to that time, the promontory hosted both an Arab and Byzantine fortification. The castle was somewhat destroyed in a siege at the turn of the 13th century when Frederick II of Aragon attacked his once faithful admiral, Roger of Lauria.
The remaining portion of the fortification is now a small civic museum. If you’re sporting comfortable, sturdy shoes, you can climb to the top of the castle to see the views of the Riviera dei Ciclopi or Cyclopse’s Riviera.