Castle of Norman origin (Castello Normanno) is located in the centre of Adrano, built in 1070 on behalf of Norman king Roger I. They probably built the keep on the ruins of a pre-existing Muslim fortress at this site. Its purpose was to ensure control over a large portion of the surrounding Etna area.
Inside the castle is the archaeological museum with antique findings of the region.
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.