The Church of Saint David in Llywel is said to have been dedicated to three saints: David, Darn (Paternus), and Teilo; and known as Llantrisant. Its name was changed when it was granted to the Chapter of Saint David sometime between 1203 and 1229. The nave and chancel date to around 1480, but the tower is slightly earlier. Though the body of the church was restored by Sir George Gilbert Scott in 1869, what we see is almost entirely a product of the 15th century and earlier.
The church displays Perpendicular Gothic architecture. The grave of the writer and preacher David Owen (Brutus) is in the churchyard. As well holding a copy of the famous Llywel Stone, the Church holds the original Aberhydfer stone and old village stocks.
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.