St. Paul's Church (Pauluskirche) was constructed between 1898 and 1901 by Karl Moser (1860–1936) and Robert Curjel and features a Neo-Romanesque architectural style. The apse is fitted with a stone pulpit that is raised behind a stone communion table. The apse also features a gallery, with a central arch behind the pulpit, in which the organ and choir are placed.
It features artwork in Art Nouveau style including relief work on the church exterior above the main entrance by sculptor Carl Burckhardt (1878–1923), mosaics on the inner front wall by Heinrich Altherr (1878–1947) and stained glass windows by Max Laeuger (1864–1952).
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.