Teutonic Castle Ruins from the 14th century with the high tower (56 m high) has been survived to the nowadays in Brodnica. The castle was the headquarters of the commander of Brodnica and was one of the most powerful Teutonic castles. During the 13-year war was occupied by the Polish army in 1454 and 1463. From 1479 to the partition of Poland in 1772 the castle was the seat of Polish mayors (1485-1604 Działyński, and the most famous: princess Anna Vasa 1604-1625). The castle was destroyed during the Swedish wars in the 17th century and in the years 1785-1842 was partially demolished by order of King Frederick II of Prussia. The castle is adjacent to the northwest part of the city walls, used to protect one of the most important passages on the River Drwęca. Built on a square plan with an inner courtyard, surrounded by a moat and linked to the flowing beside Drwęca.Currently in the basement of the castle the museum exhibition is located.
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.