Most of its boundary has vanished into the ordinary fabric of the landscape, cut through by a road in the north-west and south-west, and interrupted by a field wall at the north and south-east. What survives is fragmentary: stretches of an earthen bank, with traces of an external fosse, the shallow ditch that once ran around the outside of the enclosure, visible from the north-west around to the north, and again from the south-east sweeping through the south to the south-south-west. It is the kind of monument that rewards patient looking, its shape more apparent on a map than on the ground.

Circular ecclesiastical enclosures of this kind are characteristic of early medieval Ireland, typically associated with the founding of a church or monastic community, often pre-Norman in origin. The circular form, defined by a bank and fosse, was both a practical boundary and a sacred one, marking off consecrated ground from the surrounding world. At Killooaun, the enclosure still contains a church and a subrectangular graveyard within its interior, which suggests continuity of religious use across many centuries. The graveyard has yielded at least one quiet surprise: according to local memory, a quernstone, a hand-operated grinding stone used to mill grain, was found there some years ago. Such an object points to domestic or agricultural life alongside the spiritual, a reminder that early religious communities were working settlements as much as places of worship.