Isselburg tower is one of the rare preserved medieval constructions of the town, a part of the former town hall. Initially the towers were four in number. They appeared as soon as Isselburg received town rights in 1441. This particular keep tower is 15 meters tall, with walls 1.75 meters thick.
Today Isselburg tower is covered with a tile roof, while initially it was open on the top, with castellation and loopholes. In the past it was adjusted for permanent residence of the sentry: there was a living room and a kitchen with a fireplace inside. Today there is an exhibition in the tower displaying medieval furniture, tableware, and copies of old armour.