The Manningaburg castle in Pewsum dates back to the year 1458 and was originally - as the name suggests - the headquarters of the chief family Manninga. However, in 1565 the castle was sold from Chief Haiko Manninga to Count Edzard II Cirksenas. Unlike most castles in Ostfriesland, Manningaburg is open to the public and houses a museum dedicated to the chief and castle history. In the ceremonial hall of the castle, you can get married in a civil ceremony.
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.