Grudziądz is one of the oldest towns located by the Teutonic Order on the Chełmno land. The first fortifications began to be built after the location taking place in 1291. During the Middle Ages, they were increased and modified several times. In the 14th century, 10 towers were erected within the walls, and the wall on the edge of the escarpment from the Vistula side was gradually replaced with a line of defensive multi-storey granaries. In the fifteenth century fortifications consisted mostly of a double line of walls with 4 gates. In the 17th century, additional earth fortifications were built in front of the Side Gate, while the medieval walls were reinforced with scarps in many places. In the second half of the nineteenth century, due to the dynamic development of the city, most of the fortifications were dismantled and the moat was filled up.
The fortifications of the town were erected on a plan similar to the extended quadrilateral, situated along the river. Initially, it consisted of a single line of brick defensive walls and a moat, connected in the north-western part with previously erected fortifications of the Teutonic castle. The circumference of the town defense walls was reinforced with 10 towers. They were rectangular in plan and open from the town side. Only the southeastern tower had a plan of a closed quadrilateral, and the tower north of the Side Gate was round. From the side of the Vistula, the defensive line has been replaced by storey granaries. In the fifteenth century, a second, outer, lower defensive wall was added from the south and east. The irrigated moat was the outer defense zone was.
Four gates led to the city: Toruń Gate from the south, Łasin Gate from the north, Water Gate leading to the Vistula port and a mill in the south-west corner and Side Gate from the east, leading to meadows and urban pastures. In addition, there was the Castle Gate, connecting the two defensive organisms. In the 15th century, the Toruń, Łasińska and Wodna gates received foregates, connecting with the second, outer ring of fortifications.
The rebuilt Water Gate has been preserved to our times, the lower part of which has an arched passage from the 14th century. The upper part was rebuilt for residential purposes in the 17th century. In its best condition it survived the south-east section of double walls between the outlets of Klasztorna and Szkolna streets with well-preserved fragments of the tower and the wall. A very valuable monument is the bridge from the first half of the 13th century, which is an element of the Toruń Gate site. It is possible that it was created earlier than the gate itself and is probably the oldest preserved bridge in Poland.
Webpage zamkidwory.forumoteka.pl, Grudziądz, mury miejskie.
Webpage wikipedia.org, Mury obronne w Grudziądzu.