St. Mary's Church (Marienkirche) is a large Lutheran church built some time before 1298. It is architecturally Gothic, an example of the brick gothic style prevalent in northern Germany. Between 1625 and 1647, it was the tallest building in the world at 151 metres tall.
The bell tower collapsed in 1382, and was rebuilt by 1478. In 1495, the steeple tower blew down during a severe storm, and was then rebuilt taller. This was subsequently struck by lightning in 1647, and burned down, and was rebuilt as a baroque dome, which, completed in 1708, can be seen today. The tower is currently 104 metres tall.
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.