Auerburg, Medieval castle ruin in Oberaudorf, Germany

Auerburg is a ruined stone castle on a 543-metre rock above Oberaudorf. Its low, thick walls of rough grey stone blocks form an irregular rectangular enclosure divided into adjoining sections, with a cylindrical tower fragment rising near the back. The top edges are broken, exposing rough interior stonework; no roof or flooring remains.

The fortress was built during the Middle Ages to control important trade routes running through the valley below. It served strategic purposes for the region across multiple centuries of medieval history.

The ruin is tied to the legend of the "Three Heathen Maidens of the Auerburg": three sisters, two of whom cheated their blind sibling, who cursed the castle so that it sank, leaving only the ring walls. Since 1991 the Museum im Burgtor in the late-medieval gate on the road to Kiefersfelden has displayed the castle's history.

The excavation area is freely accessible; llamas graze it to keep vegetation down. The late-medieval castle gate on the road to Kiefersfelden, a narrow passage between rock slopes, houses the Museum im Burgtor, focused on the Auerburg, since 1991.

The castle rock was already settled in the Bronze Age, long before the medieval walls rose. Archaeologists from the University of Bamberg excavated here between 1992 and 1998, uncovering buried masonry, and in 1994 a wooden bridge was rebuilt over the historic entrance. Llamas now graze the excavation ground to keep the vegetation down.