In spring 1231 Teutonic Knights crossed river Vistula at the height of Nessau and established a fortress. On 28 December 1233, the Teutonic Knights Hermann von Salza and Hermann Balk signed the foundation charters for Thorn and Che³mno. The original document was lost in 1244. The set of rights in general is known as Kulm law. In 1236, due to frequent flooding, it was relocated to the present site of the Old Town.
Torun castle was destroyed in 1454 during the Toruñ"s burgher uprising against the Teutonic Knights what in succession caused the 13-years Polish-Teutonic War ended by signing famous Second Toruñ Treaty in 1466. It was only 1966 when the ruins was explored and prepared for tourists.
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.