The track, in cutting across the northern arc of the fosse, has quietly narrowed a ditch that was already there long before anyone thought to build the farmhouse or lay the avenue. That kind of accidental layering, one era of land use nudging up against another without much ceremony, is what makes this small earthwork in Ballybrown worth a second look.

The site is a rath, the Irish term for a ringfort, which was the most common form of rural settlement in early medieval Ireland, typically dating from roughly the sixth to the twelfth century. A ringfort of this type generally consisted of a circular area enclosed by one or more earthen banks and ditches, used as a farmstead by a family of some local standing. The Ballybrown example is roughly circular, measuring thirty metres on the north-to-south axis and twenty-eight and a half metres east to west. It is enclosed by an earthen bank that survives to an internal height of about half a metre and an external height of approximately three-quarters of a metre. Outside the bank runs a fosse, a defensive or demarcating ditch, reaching around eighty centimetres in depth and two and a half metres in width. The bank is best preserved along the north-east to south-east arc, and it drops noticeably for about six metres at the south-west. The fosse holds up best on the western to north-western side, before it narrows where the modern avenue has encroached. The site was recorded by Denis Power and uploaded to the national record in August 2011.

The ringfort sits in pasture on a gently north-facing hill slope, immediately south of the avenue leading to the derelict farmhouse. Because the interior is under grass and slopes down gradually to the north-west, the earthworks read more clearly from a slight distance than from within the enclosure itself. The bank and fosse are subtle features at this scale, so it helps to visit on a low-sun day in autumn or winter, when raking light across the ground picks out the relief of the earthwork far more legibly than a summer visit would allow. The fosse along the western arc, being the best-preserved stretch, gives the clearest sense of the original form.