St Seiriol's Church, Penmon Priory Church, is formerly the Priory Church of St Augustine (for the Priory see NPRN 95543). It is a large cruciform church comprising a relatively small nave of about 1140, a later twelfth century central tower and transepts, and a dispropotionately large chancel, built at a lower level. The chancel was originally thirteenth century and is thought to have been built following the marriage of Penmon with Priestholm. It was rebuilt in the fifteenth century and again in 1855, when the north transept was also reconstructed. The chancel alone served as the parish church by 1937.

The aisleless nave retains some original features, notably the south door which has a carved beast carved on the tympanum. The two stage tower has sumptuous Romanesque arches and rises to a blunt pyramidal spire. The south transept has internal Romanesque arcading. Paintings include Queen Anne (1707-14) Royal Arms in the north transept.

Sources include:
RCAHM Anglesey Inventory (1937), 120-122
RCAHMW Wallpaintings database. 2004.09.08/RCAHMW/SLE
Refs: Inv.121b.
Richard Suggett, Painted Temples: Wallpaintings and Rood-screens in Welsh Churches, 1200–1800, (RCAHMW 2021)

RCAHMW 2022