The largest church in Bielefeld is the Neustädter Marienkirche, a Gothic hall church dating back to 1293, completed 1512. Historically speaking, this building is considered to be the most precious possession of the town. It was the starting point of the Protestant Reformation in Bielefeld in 1553. A valuable wing-altar with 13 pictures, known as the Marienaltar is also kept inside.
The baroque spires were destroyed in World War II and later replaced by two unusually-shaped 'Gothic' clocktowers. The altarpiece of the Bielefeld church Neustädter Marienkirche from around 1400 is among the most prominent masterpieces of artwork of the German Middle Ages. Two of the altarpieces, The Flagellation and The Crucifixion are now in the collection of the Metropolitan Museum of Art in New York.
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.