Poznań residents wanted to feel safe. To achieve this, they needed to erect their own defensive system to protect them in the event of a siege. In the 14th and 15th centuries, Poznań’s aging fortifications were replaced with a ring of sturdy city walls measuring 1700 m in length and 7 m in height. The city was accessible via four guarded gates. During crises, Poznań was defended not only by its military, but also by the burghers. Craftsmen, who were associated in guilds, were assigned to defend a specific section of the wall and specific keeps, hence their names, which include Tailor’s, Chimney Sweep’s and Butcher’s keep. Whenever the city faced financial difficulties, some keeps were rented out as residences. One of them was also incorporated into the St. Catherine cloister complex, and has survived to this day. Some of the city walls were dismantled in the 18th and 19th centuries. Their location is marked on the pavements in the Old Town with a red brick line.