It is a small but disorienting detail, and it sets the tone for a church that has been accumulating quiet contradictions for centuries. The walls of this medieval parish church at Mahoonagh Beg stand mostly to their full original height, built of uncoursed limestone rubble, open to the sky, and partially consumed by ivy, which has by now swallowed the west gable window entirely.

The fabric of the church rewards close reading. The east window retains a light with simple Y-tracery, the kind of forked stone division that splits a window opening into two pointed arches, and its embrasure is deeply splayed, drawing light inward. Several of the edge stones here are sandstone rather than limestone, reused from an earlier window and identifiable by their carved moulding. A round-arched window in the south wall is particularly unusual: both the arch of the light and its plain hood moulding are carved from a single stone, a detail noted by the antiquarian T. J. Westropp when he recorded the church in his 1904 to 1905 survey. Near the south-east corner, a small rectangular recess in the wall is either an aumbry or a piscina, the two being related liturgical fittings used respectively for storing sacred vessels or for draining water used in Mass. Opposite, in the north wall, a tomb niche sits partially obscured by ivy. Its semi-circular arch carries a moulded edge that rises into an ogee arch topped by a finial, with matching finials on thin pilasters to either side. The style places it in the fifteenth or sixteenth century.

The ruin sits south of centre within its graveyard, which remained in use long after the church itself fell. The earliest legible headstone is dated 1860, the most recent 1990. The north-east corner of the building has been structurally isolated by two vertical cracks running through the masonry, so it is worth approaching the interior with some attention to where you stand. The ivy covering portions of the walls is dense enough in places to conceal architectural detail, so a visit outside the growing season, when the plant is thinner, will reveal more of the stonework, including whatever survives of that west gable window beneath the foliage.