Gothic Church of St. Catherine was built between 1310-1370 by the Teutonic Knights. In the years 1554-1598 it was used by Lutherans. After damage in 1631 and 1648 was renewed in the 2nd half of the 17th century. Three-nave hall church with square-closed chancel and the west facade with tower from the 15th century. Inside there are 15th-century starlike vaults, fragments of wall murals: Gothic, Renaissance from about 1582, and the Baroque of the turn of the 18th century. Gothic sculptures include 12 apostles at the pillars of the aisle, the crucifix dates from the late 1500s and group of the Crucifixion from the beginning of the 16th century. Renaissance stalls date from 1583.
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.