St Paulinus' Church is situated within a rectilinear churchyard, bordered by a road on its east boundary. It is located some 750m north-east of the infamous Ystafell Twm Shon Catti (Twm Shon Catti's cave) (NPRN 120251) and some 950m north of Ystrad Ffin lead mines. The number of cairns, deserted settlements and other man-made landscape features indicate that the locality was more intensely inhabited in the past than it is now. The church is thought to have first been erected in 1117. After the conquest, the church was a chapelry to Llanfair-ar-y-bryn and belonged to the medieval deanery of Stradtowy. It is first mentioned in documents of 1339, when it belonged to Strata Florida, as part of the abbey's Nant-y-bai grange. The earlier chapel was reputedly in a state of dereliction in 1810, at which time services were held in a nearby cottage. There is a spring adjacent to the church. a stream, Nant y Ffin, is some 40m from the north-west churchyard boundary. Nothing of the building's original fabric is now visible, but the earthwork platform around half the chapel may pre-date the current building.

The current church is a Grade II listed building, rebuilt in 1821 under the patronage of Lord Cawdor. It is small in size and is constructed of rubble stone. The building consists of a three-bayed nave and chancel without structural division, and a west porch. Openings date from 1821, and are plain, without surrounds. The west door and porch are similar in style. In 1878 St Paulinus' was replaced as a parish church by St Barnabas, Rhandirmwyn, and first edition (1888) Ordnance survey mapping depicts it as a Chapel of Ease. The building was restored in 1900, and a plaque commemorates this. Neo-Gothic timber frames were added to the windows, and the church was also re-roofed and re-seated at this time, as well as undergoing re-pointing. Small-scale renovations were carried out in 1984, which included some re-pointing of external brickwork.

Sources include:
Cadw, 2012, Listed Buildings Database
Cambria Archaeology, 2000, Carmarthenshire Churches, gazetteer, 48
Ordnance Survey, 1888, First edition 25inch

N Vousden, RCAHMW, 27 September 2012