Preetz Priory is a former German Benedictine monastery of nuns founded in 1211 by Graf Albrecht of Orlamünde, nephew of King Valdemar II of Denmark. He founded it following a mystical experience which he later recounted happened while he was stalking a deer. After following it into a glen, the deer stood still and he suddenly saw a gleaming cross appear between its antlers. He felt that the site was a holy place which he called the Field of Mary and, to honor the vision, founded a monastery of nuns at a location some 4 km away. A monastery on the actual site of the vision was built only in 1260.
Suppressed in the 16th century due to the Protestant Reformation, it became an aristocratic Lutheran women's convent belonging to the Schleswig-Holstein knighthood. It continues in this capacity.
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.