The result is a cashel that is only partially legible today, its original circuit visible from the west around to the north, but otherwise subsumed into the working landscape around it.

A cashel is a ringfort built from stone rather than earth and timber, typically a roughly circular enclosure defined by a drystone wall and dating broadly to the early medieval period in Ireland, roughly the sixth to tenth centuries. The example at Ballynakilla is a substantial one, measuring some 48.5 metres in diameter, which suggests it was once a reasonably significant enclosure, possibly the fortified farmstead of a local family of some standing. The drystone wall that defines it is still traceable, but over much of its circuit a later field wall has been laid directly on top of it, obscuring the earlier structure and making it difficult to read the cashel as a distinct monument. Only the western to northern arc remains unobscured, giving a clearer sense of what the original wall would have looked like.