Just south of the present graveyard at Kilmacthomas, a faint D-shaped outline in the grass marks something that most visitors would walk past without a second glance. It is a slight scarp, roughly 40 metres east to west and 27 metres north to south, curving around the southern edge of a much later, rectangular burial ground. What it traces is the ghost of an earlier sacred enclosure, the kind of curved boundary that in Irish ecclesiastical sites so often signals an older, pre-Norman foundation beneath or beside whatever came after.

The parish church once associated with this site was known as the church of Rossmire or Kilcool. By 1841 it had already been removed, a detail noted in O'Flanagan's account written in 1929 and grounded in Power's earlier work from 1897. The present rectangular graveyard, defined by a stone-faced earthen bank, a low wall of earth with stone revetment on its face, contains a Church of Ireland church that represents a much later phase of use. The D-shaped enclosure to its south, still faintly legible as a scarp in the ground, likely preserves the outline of the original early church precinct, the kind of curvilinear boundary that was common in early medieval Irish ecclesiastical settlements. Roughly 140 metres to the south-east lies St John's Well, a natural spring, which points to a wider sacred landscape clustering around this gentle south-facing slope.

The well, the vanished church, and the barely visible curve of the old boundary together make this a site where several layers of religious history occupy the same quiet piece of ground, each generation leaving just enough trace to complicate the picture for anyone paying attention.