St Cwyfan's church was in existence by 1254 and was enlarged in the 14th and 15th centuries. The building later fell into disrepair, and in the 19th century parts of the church were demolished. By 1891 the surviving part was roofless, so an appeal was launched which paid for the building of a new roof. In about the 1970s all the windows were restored, but now the building is deteriorating again and a new restoration appeal has been launched.
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.