Château du Châtelier is a moated castle in Indre-et-Loire, built originally in the 11th and 12th centuries. The keep was built around 1180. The other buildings were erectd in the 15th century and later.
The castle was in Protestant hands during the Wars of Religion. In 1569 Catholic army besieged it and conquered it, but protestants escaped via underground tunnels.
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.