The first timber priory in Penmon was founded in the sixth century by Saint Seiriol, but in 971 it was destroyed by the Viking’s raid. Reconstruction and transformation into a stone building took place in the 12th century under the rule of Gruffudd ap Cynan and Owain Gwynedd. The oldest part of the priory church, that is the nave, was completed around 1140, the transept and tower were built in 1160-70, and the chancel was added in the years 1220-1240. This happened at a time when the Welsh king Llywelyn ap Iorwerth ordered north Wales convents to be reorganized according to the Augustinian rule. The monastery was dissolved in 1537, during the reign of Henry VIII. Its lands became the property of local landowners, the Bulkeley family, and were used as a deer park. However, the church remained in use, and a significant part of it was rebuilt in 1855.
The priory church is a romanesque building erected on a cruciform plan. It consists of a rectangular nave, northern and southern transepts and a square tower above them. All of these parts come from the 12th century. In the next century, a rectangular chancel was added from the east. It is quite unusual because it is bigger than the nave.
To the south of the chancel of the church, stretched a square patio surrounded by cloisters. Its eastern, western and southern sides were occupied by monastic buildings. The south range consisted of a 13th-century rectangular, two-story building housing a refectory on the ground floor and a dormitory on the first floor. From the east, adjacent to it was a square annexation from the sixteenth century, housing a warm room and kitchen above. It is not known what rooms were in the east and west ranges.
The monastery at Penmon is currently the only one of the finest examples of romanesque architecture in north east Wales. The monastery church has been preserved in a splendid condition, in a slightly worse southern range, which is a ruin. Unfortunately, the west range has been rebuilt into a modern house, and there are no visible traces of the eastern range or cloister. The priory is open to visitors for free.
Wooding J., Yates N., A Guide to the churches and chapels of Wales, Cardiff 2011.
Website castlewales.com, Penmon Priory.