But the geometry is too deliberate, the proportions too consistent. What lies in pasture on this south-facing slope at Ballykerwick is a rath, an earthen ringfort, and its dimensions tell a fairly clear story about what was once here.

Ringforts, sometimes called raths when constructed from earth rather than stone, were the standard farmstead enclosure of early medieval Ireland, built and occupied roughly between the fifth and twelfth centuries. They served as a combination of home, farmyard, and defensive perimeter for a single family or small kin group. The Ballykerwick example measures forty-eight metres in diameter, defined by an earthen bank that rises one metre above the interior ground level but presents an exterior face of three and a half metres. That asymmetry is deliberate: the bank was thrown up from a ditch dug on the outside, creating a much more imposing barrier when approached from the surrounding land than it appears from within. The low interior height is deceptive; the exterior height reflects the true scale of the enclosure as it would have appeared to anyone approaching across the fields.