The one at Ballynastockan, on a gentle north-west-facing slope in County Wicklow, is a little different. Its enclosing bank describes a D-shape rather than a full circle, measuring roughly 25.5 metres from north-west to south-east and 23 metres across, which places it on the smaller end of the ringfort spectrum. A rath, as this type of earthwork enclosure is known, would typically have housed a single farming family during the early medieval period, perhaps between the fifth and twelfth centuries, and the bank here, built from earth and stone with a discontinuous facing of boulders, still stands to a height of around a metre on its outer face.

The bank retains two gaps. One at the north-north-east, roughly 1.5 metres wide, is thought to be the original entrance, a narrow threshold through which people, animals, and goods would once have passed. The other, at the south-west, looks to be a later breach, probably made at some point in the post-medieval period when the enclosure had long since lost its function and local needs took precedence over preservation. There is no visible fosse, the defensive ditch that often runs outside such banks, and the interior offers little in the way of obvious features beyond some large boulders that are set into the ground rather than placed there later. Whether those boulders once formed part of a structure or simply happened to lie within the enclosure is difficult to say without excavation.