Aiello Calabro Castle was probably buillt in the Byzantine period in the 9th century against Arabian raids. It was besieged four months by Norman count Robert Guiscard in 1065. He lost two of his nephews in the siege.
The current ruins date mainly from the 15th century. In the 16th century it was one of the most powerful castles in southern Italy. Aiello Calabro castle was destroyed by earthquakes of 1638, 1783 and 1905. Today part of curtain walls and towers remain.
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.