On May 30, 1653, Pacidus Hieber of Greifenfels, Abbot at the Benedictine Abbey of Lambach, purchased the ancient nobility seat of Au by the Traun River.
Nothing is known about the foundation of the Castle.
In the "Wallseerisch Lehensbcuh" Book of 1446 the Castle is recorded as the Knightly Manor of the Brothers "Andre Walthasar Casparin Grafm and Bartholomee".
Over the centuries, several notable people have owned or been linked with it. Many changes and improvements to the Castle have been made in the course of time. The building was completely restored and augmented, with a music room, a library, a study and a chapel added.
During the aftermath of the French Wars the Benedictine Abbey of Lambach had to sell the Castle in the year 1820. Today, Au Castle is privately owned
Castle Grounds Hiking Trail:
Au Castle is accessible by the stairs from opposite the church. The Castle still gives most a good impression of how it must have looked in its hey days. Take a walk along the asphalt road that leads down from the Castle to the banks of the Traun River. Turn right and follow the forest road that meanders through the woods with the loop taking you back to the Castle.