From the defensive, double city walls, built from brick on stone foundations in the fifteenth and sixteenth centuries, a section of about 400 meters long has survived to this day, located along Wałowa, Targowa, Bernardyńska and Szeroka streets. In Wałowa Street, from Krakowska Gate to Basztowa Street, is a Renaissance, defensive half tower, which used to defend the northern part of the walls. The semi-circular tower protruded in front of the line of the walls and was open from the side of the intramural space. Such a construction of a strong firewall without a closing wall protected the crew from gunpowder smoke during the shooting. The basteja from the first half of the 16th century has three levels with loopholes. The thickness of its walls, about one metre at the base, decreases with each level. Its half-conical roof is covered with ceramic tiles. A moat filled with water protected the town from the double line of walls. In the 19th century, the tower was absorbed by the construction of tenement houses. For years it was not visible from the street, but in the 1960s it was uncovered, reconstructed and turned into a café. In front of the tower, in place of the demolished tenement house, a square and a glass pavilion with an entrance to the Multimedialne Centrum Artystyczne were created.