The nave has been reduced almost entirely to its basal course, a low outline in the grass, but the chancel at the eastern end still stands close to its original height, its east gable rising to 2.6 metres. The Ox Mountains rise on the far side of the lake, and a steep natural hollow opens up just ten metres to the north of the building. The church's alignment follows the ridge rather than the conventional east-west Christian orientation, a practical concession to the land it occupies.

Kildermot Church, as it is named on the 1922 Ordnance Survey six-inch map, is a modest nave-and-chancel structure, a common form in Irish Romanesque architecture where a rectangular nave for the congregation connects to a smaller chancel reserved for the clergy. The chancel is about 0.8 metres narrower than the nave, and the step-change in width marks a boundary that would once have been emphasised by a carved stone arch or doorway; displaced fragments of worked stone found inside suggest this feature existed, though nothing survives in place. The chancel walls are built of mortared random rubble with large squared quoins at the corners, and the east gable rests on a projecting stone plinth designed to level the wall against the natural slope of the ridge. Centred in that gable is a narrow round-arched window, barely 0.25 metres wide on the outside but splaying inward to well over a metre. Two small hemispherical notches cut into the base of the arch on either side were almost certainly made to hold a frame for a wooden shutter or screen. The same wall also retains two small wall recesses, one square and one L-shaped, used to store altar vessels. A holy water stoup and further cut stone fragments have been set in concrete along the south wall of the chancel. The narrow level ground to the east and south of the building served as a children's burial ground, a cillín, the kind of unconsecrated or informally consecrated space used across Ireland for the burial of unbaptised infants and others excluded from the main churchyard.