The building of defense walls in Olsztynek was started after 1414, after the so-called the Hunger War, when the Polish army seriously destroyed the town and its surroundings. The last time their proper condition was noticed, was during the Thirteen Years War in the second half of the fifteenth century. In the 17th century, the entire town was severely damaged by the Swedish wars. The devastated the town walls were no longer an effective defense against cannonballs. After a fire in 1685, the towers were adapted to houses. As a result of another fire in 1804, the German Gate located near the castle was destroyed, and the subsequent years of the 19th century caused further damages to the town’s fortifications, which were treated as an easily available source of building materials. The moat surrounding the town was filled up and turned into gardens.
The line of fortifications ran along an irregular rectangle. The length of the entire wall was about 1000 meters, the height reached 9 meters, and the thickness at the widest point at the base was up to 2 meters. A fieldstone was used to build the foundations, while the upper parts of the walls were erected with a brick. Although the upper fragments of the walls have not survived to our times, it can be assumed that they were crowned with a sidewalk and battlement made of bricks. The defensive wall was strengthen with half towers, opened from the side of the town, which were all together 13. South East section had a round, corner tower and six half towers, open from the town, spread every 20-30 meters. There were three half towers in the south-west and there were five half towers in the northwest section. In the north-east, apart from the castle gate and fortifications, there was not a single tower. Two gates led to the cities: High, also known as the German, next to the castle and Nidzicka, called Poland in the southern part of the walls. Outside the walls there was already unreadable moat, fed by the water of the Jemiołówka river.
To this day, the defensive walls in Olsztynek have survived on a large part of the original perimeter, unfortunately in a heavily reduced form. Town gates have not survived. Of towers in the best condition is the so-called Mrongowiusz’s house, that is a half tower, transformed into a parish.
Website zabytek.pl, Miejskie mury obronne Olsztynek.