Bederkesa is a medieval castle built originally in the 12th century. Its original owners, the counts of Bederkesa, lost their fief in 1381. For more than two centuries, the City of Bremen became owner of this castle and its surrounding subjects. As a symbol of sovereignty, they have constructed a Roland statue which is still standing in front of castle. Until 1859, this castle served as administrative centre of its surrounding area. In 1881, it was sold to local investors who converted it into a hotel. This hotel, however, became ramshackle and was deemed to demolition, when the local county administration bought it in 1975, spending much money for reconstruction. Since 1982, the castle serves as museum of local archeology. Remains of prehistoric and medieval houses have been dug from three abandoned villages, Fallward, Feddersen and Flögeln. These Anglo-Saxons moved to England around 450 AD and left their villages uninhabited.
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.