The remains of St Mary's Church stand within a rectilinear churchyard overlooking a landing point on the shore of Garron Pill on the eastern shore of the Daugleddau. The site may have early medieval origins. The original form of the churchyard is not known, as it was remodelled, along with the adjacent farm buildings and the surrounding landscape, by the Lawrenny Estate in the 18th and 19th centuries. The church was formerly a chapelry, mentioned in the 13th century as `Merthyr Cynlais?; the `merthyr? element suggesting origins as a pre-Conquest `martyrium?. It was a donative free chapel, (re)established by the patron. The church was a parish church in the post-medieval period. It is now in private hands.

The church was reportedly 'in decay' in 1600, but is thought to have been rebuilt sometime before 1753. It is now a ruin.

Sources include:
Dyfed Archaeological Trust, 2000, Historic Churches Project, Pembrokeshire gazetteer
Dyfed Archaeological Trust, 2003, Early Medieval Ecclesiastical Sites Project, Pembrokeshire gazetteer

N Vousden, 21 November 2017