The church of St Levan is medieval. It was heavily rebuilt in the twelfth century and extended in the fifteenth century. In 1874 it was restored by J. D. Sedding to a more medieval appearance.
St Levan (properly Selevan, a Celtic form of Solomon) according to the Life of St Kybi was a Cornishman and the father of Kybi. In the department of Morbihan are four places probably connected to the same saint, who probably lived in the 6th or 7th century. On the cliff at St Levan is St Levan's Well and below it the probable remains of his chapel.
The tower contains three bells dating from 1641 (John Beaskam), 1754 (Abel Rudhall) and 1881 (Mears & Stainbank).
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.