The Carmelite Church is Gothic and was built in the 14th century. It has a wealth of treasures, including gravestones and the choir stalls (15th century). That the Carmelite monks honoured Our Lady can be seen in the many illustrations of Mary e.g. the Grape Madonna (outside the church), the Madonna in the Rosary and the Pieta. The former Carmelite monastery is now the Town Hall.
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.