That survival alone is unusual, but what makes the building quietly compelling is the layering of evidence it contains: openings blocked and rebuilt at different periods, a massive outer lintel of very dark grey limestone over two metres long, and the ghost of a doorway on the east wall that has been rendered invisible from outside by later rebuilding. The church was recorded as a national monument, and its fabric rewards close attention in a way that a tidied-up ruin generally does not.

The site is associated with a monastery founded by Neasán of Mungret, a figure connected to the early ecclesiastical settlement at Mungairit on the outskirts of Limerick city, whose feast day falls on the 25th of July. The antiquarian T. J. Westropp, writing in 1904 to 1905, described this church as the oldest of several on the site and suggested it might date to the tenth century, noting its inclined door jambs and round-headed windows, features broadly consistent with pre-Norman Irish church building. The 1989 Urban Survey, compiled by Bradley and colleagues, was more cautious, recording the building as possibly pre-Norman but resistant to precise dating. The masonry is coursed limestone rubble, a construction method in which roughly shaped stones are laid in approximate horizontal courses, with quoins, the corner stones, of mainly limestone and some dressed sandstone. The plinth on which the church sits, modest at eighteen centimetres wide but up to forty-five centimetres high, is another detail suggesting some ambition in the original construction.

The church lies immediately south of the Foynes road, which makes it relatively straightforward to locate. Inside, the round rear arch of the western window in the south wall remains visible, and one splay of the eastern window can also be seen; a splayed window is one whose opening widens inward, funnelling more light into the interior. The east wall carries a round-headed window and, below it, a blocked doorway that only becomes apparent from the inside. The outer lintel of the west door is worth examining closely, a single rough-dressed block of very dark limestone, and the inclined jambs, sides that lean inward slightly rather than running perfectly vertical, are a detail Westropp singled out more than a century ago. The north wall has nothing to show internally, which in its own way is part of the record.