St Tanwg's Church, Harlech is located in close proximity to the town centre. It is situated within an irregularly shaped churchyard, bounded by the B4573 on its south-west side. The church was opened in 1841 and was built to replace St Tanwg's, Llandanwg (NPRN 43901), which had fallen into disrepair and was abandoned in 1845.
Built to designs of Thomas Jones of Chester, the church is constructed in a simple lancet, pre-ecclesiological style, largely unaltered. It is of slate stone construction with coursed, squared blocks, and buff sandstone dressings, a shallowish slate roof with coped and kneelered gable parapets and gable cross to the east, a tiled ridge and moulded sandstone eaves. Its plan consists of a three-bay nave with small two-bay, step-down chancel, and a short north aisle. Between nave and chancel is a twentieth-century, corrugated iron lean-to on brick piers extruded in the north-east corner between the two. On the west is a gabled bell-cote, corbelled-out slightly to the west and with a segmental chamfered bell opening.
The interior is plain with plaster removed from all nave walls except around the chancel and south transept arches. The roof is of seven bays with straight braced collar trusses with king-posts and small raking struts above the collars. Other interior features include slate-flagged floors, a simple octagonal oak pulpit, simple Gothic oak choir stalls, and twentieth-century altar rails.
The fifteenth century Perpendicular, octagonal sandstone font was removed from the predecessor church to the new church when it was abandoned.
St Tanwg's Church, Llandanwg was restored in 1884, and both churches have been in operation since that time.

Sources include:
www.twyni-llandanwg-dunes.org.uk
Cadw Listing database

David Leighton & N Vousden, 11 November 2014