At Castletimon in County Wicklow, a cylindrical granite baptismal font, presumably in use here for centuries, was at some point removed to St Mary's church at Barndarrig, in Ballinacor West townland. What remains on site is a nave and chancel church overlooking the valley of the Potters River, its western gable still standing to its original height of five metres, and a bullaun stone sitting outside the south-west angle of the building. A bullaun is a boulder or outcrop with one or more deliberately ground hollows, often associated with early ecclesiastical sites and sometimes linked to ritual or healing traditions. This one, oval-basined and granite, is among the more quietly intriguing things the site has to offer.

The church itself is built of roughly coursed rubble in the nave and chancel arrangement typical of medieval Irish ecclesiastical architecture. The nave measures approximately 15.4 metres east to west and 6.85 metres north to south, while the chancel is almost square at around 4.5 by 4.45 metres. Much of the south wall of the nave has been lost, but the north wall survives to near its full height of between 2.9 and 3.1 metres, interrupted by a two-metre-wide break that may once have held a window or door. The western gable carries an opening towards its southern end with a protruding door portal, noted as possibly original but unusual for this type of structure. A modern wall now divides nave from chancel, though the two sections appear to have been built at the same time. Within the ruined nave, two graveslabs dated to 1723 still lie in place, and the surrounding graveyard holds a substantial collection of eighteenth-century headstones. The enclosure itself, roughly sixty metres across, retains much of its original earth and stone boundary bank, up to three metres wide at the north-east, with a narrow drainage ditch running inside it along the northern and southern edges. Part of the eastern bank was replaced at some point, probably in the nineteenth century, with a mortared stone wall, and beyond it lies a wide, flat-bottomed natural gully that would have helped define the boundary of the sacred precinct long before the bank was raised.