Château de Brax was originally constructed in the 13th century, but there were alterations and additions in the 16th and 18th centuries. The structure is enclosed by four circular towers. The rear façade incorporates the grand staircase. The brick walls are crenellated. The front opens onto parkland; access is by a double staircase. A round walk carried on machicolations formed of brick corbels and blind arcades circles the whole building.
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.