The Church of Saint-Pierre (Église Saint-Pierre) was built in the early 13th and the construction continued until the 16th century. The spire was destroyed in 1944, and has since been rebuilt. The eastern apse of the church was built by Hector Sohier between 1518 and 1545. The interior choir and the exterior apse display an architecture that embodies the transition from Gothic to Renaissance.
Until around the mid 19th century, the eastern end of the church faced onto a canal that was then covered and replaced by a road. Various artists and engravers recorded this relation of the church to the canal; for instance, the Scottish painter David Roberts made several very similar views, one of which (dated to c.1830) is in Musée des Beaux-Arts in the Château de Caen.
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.