St Twrog's Church is situated within a rectilinear churchyard, bounded by a 1m high stone wall. It is accessed via a timber framed lych gate (1897) in its eastern boundary, to which there is a narrow path between two houses. The churchyard is located less than 100m from the high water mark of the Afon Dwyryd, and is likely to have been liable to flooding in the past. There are three old yew trees to the south of the church. The stone of Twrog (Maen Twrog) (NPRN 302918), a sandstone pillar, stands to the east of the south porch (adjacent to the oldest gravestone, dated 1691). The standing stone features in the Mabinogi as the burial place of Pryderi, slain by Gwydion. According to local legend, Twrog threw the stone down from the top of the Moelwyn, crushing a pagan altar in the valley.

Few details are known of the medieval building, although it is known to have had two aisles.

The church was rebuilt in 1814, on the footprint of its medieval predecessor. The building is depicted on historic (1889) Ordnance Survey mapping as rectilinear in plan.

The present church is a Grade II listed building, constructed of rubble stone with sandstone dressings. It dates to 1896, and replaced the 1814 building. It possibly incorporates medieval fabric in the lowest courses of its north and east walls. The current building consists of a nave with narrower chancel, north vestry, south porch, and a square tower with spire. The porch is half-timbered on a stone plinth base. Its inner doorway has a datestone above it, which bears the inscription 'THE NAVE OF THIS CHURCH WAS / REBUILT ON OLD FOUNDATIONS / WITH THE ADDITION OF CHANCEL / TOWER AND SPIRE ? AD ? 1896 ?'.

Sources include:
Cadw, Listed Buildings Database
Beverley Smith, J, Beverley Smith, Ll, 2001, History of Merioneth II, 364-5
Gwynedd Archaeological Trust, 2000, Historic churches of Gwynedd: gazetteer, 391
Ordnance Survey, 1899, first edition 25inch

Nikki Vousden, RCAHMW, 27 April 2012