What survives is very little: only the south-western angle of a rectangular rubble limestone building, roughly twelve metres by seven and a half, with walls that once stood to a modest height. A portion of the south wall remains upright, braced by what earlier observers described as buttresses running along its full length, though these features are now thought to be a base-batter, a thickening at the foot of a wall that splays outward to provide stability and resist lateral pressure. The entrance doorway, framed with unhewn stones, opened through this south wall, but only one jamb is left standing.

The church's long history begins with a grant made in 1203, when William Marshall, Earl of Pembroke, gave two carucates of land here to the Augustinian Priory of Kells, located some nineteen kilometres to the south. Ardaloo functioned as a grange of that priory, meaning it was an outlying agricultural estate managed by the canons. The land changed hands more than once: the first Prior, Reginald, leased it to Simon fitz John Layles, but Simon's son William fitz Simon restored it to the priory by deed on 24 December 1267. By around 1300, the church at Ardaloo appeared in a Taxation of Ossory as part of the Deanery of Odoch. In 1412, King Henry IV formally confirmed the chapel to the Priory of Kells. By 1540, the last Prior, Philip Howleghan, still held land here, recorded as three messuages, fifty acres of arable and twenty of pasture. Within forty years, the Dissolution had run its course, and in 1578 Thomas, Earl of Ormond, received a Crown grant of the place, marking the end of any monastic connection.

The ridge on which the ruin stands is now largely reclaimed pasture, and the surviving masonry sits at a spot that commands wide views across the confluence below. The steep eastern and southern slopes drop sharply to the river flood plain, while the ground falls more gradually toward the Nore on the west.