The late-Gothic Langendorf moated castle near Zülpich is renowned as the best well-kept of its kind between the Eifel and the plains. The Langendorf castle was the ancestral home of the Lords of Gertzen, a powerful dynasty. Within the building there is a courtroom with mighty vault arches, a dungeon, a chapel and lavatory bays. The castle is home to an international historical collection of fireman helmets.
The Manfred-Vetter foundation for art and culture had a large granite stele erected in the castle grounds, in memory of the sculptor Ulrich Rückriem with the motto "Art in the countryside".