In the middle of a graveyard in Ballynafagh, County Kildare, a single stretch of wall is just about all that remains of a medieval church. Six metres long, two metres high, and less than a metre thick, the surviving north wall is built of rubble limestone masonry, a mix of large unworked boulders and smaller field stones set around a mortared rubble core. A partially robbed-out window embrasure sits just east of centre, its stonework plundered at some point in the past, and a loose dump of stones still lies against the wall's southern face. It is, by any measure, a modest remnant, but it carries a name that reaches back into the medieval Latin of ecclesiastical record.

The church was dedicated to the Blessed Virgin and appears in Dr Mac Geoghegan's list under the title 'Ecclesia Sanctae Mariae do Ballynaffaghy'. By the mid-eighteenth century it had already been reduced to a landmark rather than a working building: Noble and Keenan's 1752 Map of County Kildare marks it, and Taylor's 1783 Map of County Kildare labels it plainly as 'Church Ruins'. The building stood near the south-east corner of what became the later parochial church, and the two structures occupied the same graveyard, the older wall effectively absorbed into the churchyard landscape around it. That layering of sites, one church outlasting and eventually overshadowing another, is a pattern found across the Irish countryside, where medieval foundations were often built upon, cannibalised for stone, or simply left to subside beside their successors.