Ehrenberg Castle dates from the early 12th century when it was built by the Counts of Lauffen. The oldest part of the wall around the main castle. The building of the main castle date from the 12th and 13th centuries. To existing keep dates from 1235. The castle was ruined in the Thirty Years' War. The new residential and farm buildings have been built in the 17th and 18th century. Today Ehrenberg is privately owned and can not be visited.
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.