The western end of this former parish church of Muckalee, dedicated to the Blessed Virgin, has slightly thicker walls than the rest, and the remnants of corbelled stones projecting from the south wall suggest the presence of a stone vault overhead. The most plausible reading of these details is that the western portion functioned as a residential tower, a not uncommon arrangement in medieval Irish ecclesiastical buildings where defence or secure lodging was a practical concern, but one that sits oddly against the conventional image of a simple rural parish church.

The church itself is roughly rectangular, measuring about 22 metres east to west and just under 7 metres north to south, built of well-coursed masonry. Writing in 1905, the historian William Carrigan recorded that it had been divided into a nave and chancel, though the wall separating them had by then been almost entirely reduced to ground level. A large buttress, nearly 2 metres on each side, reinforces the south wall roughly 4 metres from the west gable, and the east gable retains a base-batter, a thickening at the foot of the wall that helps to resist outward pressure. By 1839, when Ordnance Survey investigators were compiling their letters on the region, the east gable still contained an ogee-headed window, a window with a curved, pointed arch in the late Gothic manner, described in precise detail at the time: four and a half feet high, a foot wide at the base, tapering to ten inches at the springing of the arch. That window is now gone; only the splayed interior embrasure remains. Elsewhere around the graveyard, architectural fragments lie scattered, among them a wedge-shaped stone step that implies the church once contained a spiral stair, presumably serving the vaulted western tower. Carrigan also noted that the west gable carried a square perforated belfry, a small open bell-tower of the kind common in medieval Irish churches, though nothing of it survives above ground level today.