The castle was built in the middle of the 11th century as a permanent house on the back of the Manhartsberg and was probably the seat of the minstrel Ulrich von Sachsendorf in the 13th century.
In a document from around 1180/1185, Alhart de Sassendorf is named as the first documented owner of the Kuenringer. Later owners included Ulrich von Sachsendorf (mentioned in 1230 and 1249), Ulrich der Zink von Sachsendorf (1340), Niklas Pillung von St. Gilgenberg (1384) and Konrad von Kreig (1430). In 1475 Wilhelm von Missingdorf transferred Sachsendorf to the Fellabrunners in Losensteinleiten after several changes of ownership. Towards the end of the 1570s, the castle was destroyed by Hungarian troops and never rebuilt.
The area of the castle is surrounded by an earth wall and covers an area of around 3,600 m². Individual finds of wood and pottery prove that there were already unfortified wooden huts on this swampy spot in the middle of the 10th century, which was supplemented towards the end of the century by a stone tower with walls 1.5 meters thick. Although the tower was demolished again in the 11th century, the area was still protected by wooden palisades afterwards. In the middle of the 13th century the construction of a fortified castle, which was surrounded by a rectangular curtain wall, began.
Archaeological excavations starting in 1987 uncovered the remains of a Romanesque chapel with a recessed semicircular apse from around 1180/90. The walls have been preserved up to a height of around 1.5 meters and some still have the remains of the original plaster. West of it are the remains of a former residential tower with a wall thickness of about three meters.
Part of the former wooden palisades was reconstructed in the 20th century. Information boards provide information about the building history. Unfortunately, these are already badly weathered and hardly legible.