St Cadwaladr's Church is a Grade I listed church in Llangadwaladr, Anglesey. The church is built in the perpendicular style. The nave is dated to the 12th to early 13th century and the chancel to the 14th. Considerable additions were later made in the mid 17th century, with the north chapel in 1640 and the south chapel in 1661. In 1856 the church underwent restoration, at which time to south porch was added.
In the newer part of the churchyard, south of the church, are war graves of four British airmen and a Polish airman of World War II.
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.