The Castello di Milazzo is located on the summit of a hill overlooking the town, on a site first fortified in the Neolithic era. The castle was built as a result of the strategic importance of the Milazzo peninsula, which commands the Gulf of Patti, the body of water that separates Sicily from the Aeolian Islands. It also commands one of Sicily's most important natural harbours.
The Greeks modified it into an acropolis, and it was later enlarged into a castrum by the Romans and Byzantines.
In around 843, the Arabs began to build a castle on the ruins of the Greek, Roman and Byzantine fortifications. The castle's keep possibly dates back to this era. The castle was enlarged by the Normans and Swabians. It was extensively modified during the reign of Frederick II of Hohenstaufen.
Between 1496 and 1508, the Aragonese built walls with six semi-circular bastions, encircling the original medieval castle. Between 1525 and 1540, the Spanish built bastioned fortifications around the Aragonese walls and the settlement which surrounded it, expanding the castle into a citadel. The new fortifications were designed by the military engineers Pietro Antonio Tomasello and Antonio Ferramolino. Some outworks were added in the 17th century. Several civil buildings began to be built within the walls of the castle, including the old cathedral and various palaces.
The castle was in Habsburg hands in the first half of the 18th century, before being taken over by the Bourbons. The latter retained the castle until they lost Milazzo to Giuseppe Garibaldi in 1860. The castle was subsequently converted into a prison in 1880, and underwent a number of alterations. The prison closed in 1959 and the castle remained abandoned for a couple of decades.
It is now in good condition, and open to the public.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.