First mentioned in historic documents in 1254, Burg Groppenstein was built in a particularly beautiful place, where the River Mallnitz flows into the River Möll. In the 15th century it was turned into a defence in the style of the late Middle Ages. In 1872 the castle was renovated by the Viennese architect Adolf Stipperger, and its exterior design has since been unchanged.
The Romanesque wing was replaced by Gothic dwellings and weirs with towers and battlement walls. The Knights Hall features beautiful, 16th century stained glass windows. Other glass paintings were added by Prof. Franz Chvostek, who owned the castle from 1936 to 1944.
Also worth a visit is the castle chapel consecrated to St. Katharina with its gothic aisle and semi-circular Romanesque apse.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.