The Groß Raden Archaeological Open Air Museum is in a depression that borders directly onto the lake of Groß Radener See. On a peninsula in front of that lies its circular castle rampart, visible from afar, which has a diameter of 50 metres. From 1973 to 1980 extensive excavations were carried out here, led by Ewald Schuldt, during the course of which the remnants of a Slavic settlement dating to the 9th and 10th centuries was unearthed. The fort has been reconstructed based on the excavations and established as an archaeological open-air museum. It has been enhanced by finds from the Slavic castle of Behren-Lübchin.
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.