A church by the name of Saint-Pierre existed in Avignon already in the 7th century. The collegiate church was founded in 1358 with the construction of the canons' building and the cloister, the apse and the belltower. Side chapels were added in the 15th century, and the nave enlarged. Outstanding carved wooden doors with decors from the late Renaissance period. Several sculpted works inside, and paintings by Simon de Châlons, Parrocel and Nicolas Mignard. Relics of Blessed Pierre de Luxembourg.
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.