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Site Details

NPRN 527

Map Reference SH68SE

Grid Reference SH6517382160

Unitary (Local) Authority Isle of Anglesey

Old County Anglesey

Community Llangoed



Period Medieval, Early Medieval

Site Description 1. Puffin Island is a Site of Special Scientific Interest (SSSI), home to at least 10 species of seabird including Puffins, Guillemots, Razorbills, Cormorant, Kittiwakes, Herring Gulls, Great and Lesser black-backed gulls, Fulmars and shags ( There is no public landing allowed on the island without the prior permission of the landowner.

2. The monastery on Priestholm is thought to have been an early medieval foundation. It was associated with Penmon Priory (NPRN 95543), itself an Augustinian house when it was granted to the Prior and Cannons of Priestholm in 1237. Following this the Prior of Priestholm shifted to Penmon. There are remains of a church, notably the twelfth century tower, and other monastic buildings, ranged within and about a walled enclosure.

The enclosure is an elongated oval, roughly 80m north-east to south-west by 36m, with several subdivisions and an inturned entrance at the south-west end. The church had a central tower, nave, chancel and south transept. The tower rises through two stages to a low pyramidal stone roof. It has plain round headed arches. Excavations in 1896 uncovered a small early chancel, possibly pre-dating the tower which appears to bear the scar of its vaulted roof. The later chancel is thirteenth century. The transept was overlain by a cottage, habitable in 1896.

There are traces of a complex range of buildings along the enclosure wall north-west of the church. Human bones are said to have been found in the area north-east of the church.

The monastic enclosure connects with various other boundary walls and enclosures.

Sources: Hughes in Archaeologia Cambrensis sixth series I (1901), 85-108
RCAHMW, 1937. An Inventory of the Ancient Monuments in Anglesey, London: HMSO, pp. 141-4, Frontispiece, Plates 185-6.
Carr, A. 'Medieval Anglesey' (1982), 287-8

RCAHMW, February 2011

3. The ruins of the church were selected for survey as a designated baseline study site for the EU-funded CHERISH Project (2017-2021) due to their general inaccessibility, their protected status and for the purposes of monitoring the structures following conservation works to the tower circa. 2009.

An initial visit was made to the island on 21st June 2018 by staff from the Royal Commission's CHERISH Project in the company of a Cadw Field Monument Warden (J. Spencer) and Dr Jonathan Green, Liverpool University, the current Licence Holder. The church tower and associated buildings stand in a clearing in dense elder woodland. The approaches are overgrown, largely obscuring the wider remains of the monastic enclosures and walls planned by Royal Commission staff for the 1937 inventory when the island vegetation was open, grazed pasture. The immediate environs of the buildings are more clear, but still surrounded by waist-high vegetation which was cut and cleared (with permission) on arrival. The walls of the church and cottage on the west and south sides are grown with ivy. The main survey work on this visit was to complete a new laser scan survey of the church for Cadw and the CHERISH Project.

A second visit was carried out on 26th November 2018 with the purpose of undertaking drone photogrammetry of the top of the tower and other upper surfaces of the ruins which were inaccessible to the earlier ground-based laser scanning, completing the baseline monitoring survey for the standing structures. A rapid record was also obtained of the standing buildings:

Tower: East Wall; East arch: 2.73m high x 1.55m. Possible Roman box flue tile in wall above arch. Traces of pitched roof fitting above. North wall; No arch. Small window in upper storey. Protruding masonry low down on NW corner suggesting intention to link to additional wall or structure. West wall; Arch, 2.5m high x 1.76m wide. Blocked. Small putlog hole midway up wall below pitched roof fitting. Inside tower: Arch in south wall roughly blocked with masonry, preserving smaller narrow inner door 1.14m wide within blocking. Arch in W wall neatly blocked with slight recess. A small pile of numbered, dressed stone has been stored in the inner NW angle of the tower.

Other external buildings. Ruined cottage on south side of tower. Blocked archway into tower on south wall, with small Romanesque arch above. Plaster line high up on tower of shows line of former pitched roof line. East and West cottage walls standing 1.8m-1.9m high but heavily grown with ivy with much loose stone at upper levels. Eeast wall has simple central window. The south wall of the cottage preserves a fireplace and chimney breast. The fireplace opening measures 0.83m x. 0.90m with a large lintel stone of contrasting red sandstone. Floor littered with tumbled masonry and roof slates.

Room adjoining on west side of cottage, accessed through door in west wall. Walls heavily ivy grown, standing internally c. 2m high. Floors infilled with rubble throughout.

Wall footings on the east side of the tower, ?nave. Walls standing 6-8 courses high, generally surviving 0.6m - 0.7m high. Infilled with tumbled rubble. Vegetation cleared here during summer 2018 visit with obvious benefits to the visibility of the standing structures.

T. Driver, D. Hunt, L. Barker, RCAHMW/CHERISH Project, Nov 2018

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