The Hoyerswerda castle is located on a hill in the center of old town. The original castle from the 13th century was repeatedly destroyed and rebuilt. Under Seyfried von Promnitz a Renaissance castle was erected from it at the end of the 16th century. Baroque elements were added in the first half of the 18th century. Since the 1950s, the castle has hosted a city museum.
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.