Châteaugiron developed around its château from the 13th century onwards, becoming more prosperous towards the end of the Middle Ages as the canvas sail industry expanded. The town’s unique historic town centre is very well-preserved and features significant remains of the medieval fortress, renovated between 1450 and 1470 by Jean de Derval. Of the six original towers, four are still standing: the 38 metre high 13th-15th century keep, built independently of the château, the 14th-15th century clock tower, a belfry during the French Ancien Regime, and the 15th century watchtower and Cardinal’s tower, whose elevated patrol paths with machicolation projections has been preserved.
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.