Gdanisko, one of the most characteristic buildings in Toruń, is the only well-preserved feature of the former Teutonic castle which is in ruins now. The tower, also referred to as Dansker, was located outside the curtain wall and served dual purpose; it was a defensive tower as well as a toilet tower. It was accessed through a covered gallery, supported by arcades, leading from the eastern corner of the castle.

The local burghers resolved to spare the tower in the course of the Thirteen Years' War (1454-1466). In 1454 when they started an uprising that marked the beginning of the war, they demolished the castle but left the Dansker intact. One of the local legends has it that their intention was to leave this "toilet tower" standing for centuries as the only relic of the Teutonic Knights in Toruń.