St. John's Church in Petersdorf dates from the 13th century. Its 64-metre-high steeple was used as a daymark by ships on the Fehmarn Belt and Sound, as it is visible for up to 20 miles at sea. The church and adjacent cemetery are surrounded by 64 lime trees. The altar triptych dating from the 14th century is considered a masterpiece of Gothic carving skill. The oldest artefact is the font of Gotland limestone. The church also contains a particularly valuable 15th century altar shrine.
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.