Château de Freundstein is a ruined castle in the commune of Goldbach-Altenbach. The castle was recorded in 1297. It ownership was shared between the abbey at Murbach and the bishops of Strasbourg. It waas given as a fiefdom to the Waldner family who still own it. In 1441, it was attacked by the Mulhouse and in 1525 by rebellious peasants. It was restored in the 16th century, but abandoned shortly afterwards. The ruins were used as a military observatory during the First World War. The ruins consist of sections of wall from the high castle, with loopholes and more recent openings.
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.