The Faulturm, also known as the Hungerturm and later as the powder tower, was a medieval prison tower in which prisoners had to serve their sentences and ultimately starve to death, causing their bodies to decay – hence the name. The tower served as a castle dungeon and was once of imposing height, comparable to that of the still-preserved chapel tower. The outer sides of the tower facing the Zwinger were faced with bossed ashlar masonry, as can still be seen on the small remaining section of the tower that survives today.

The illustration from the year 1723 clearly reveals the former tower layout of the castle complex. The tallest tower is the castle keep (Bergfried). From left to right, it is followed by the chapel tower, the gate tower of the inner castle, and finally, near the right edge of the image, the Faulturm. Once, the Faulturm formed an impressive part of the overall appearance of the castle complex. Today, only a small but characteristic remnant of masonry bears witness to its former size.