The site is a rath, the Irish term for a ringfort, a type of enclosed farmstead once so common across Ireland that several thousand examples are known to survive. This one measures roughly thirty metres across, its interior defined by an earth and stone bank between three and a half and five metres wide, rising to about one and a half metres. Beyond that bank lies a fosse, a defensive ditch about two metres across, and on the western side a second, outer bank adds another layer of enclosure. Two concentric lines of earthwork surrounding a circular interior: in early medieval Ireland, this kind of arrangement would have enclosed the dwelling of a farmer of some local standing, the outworks signalling both practical caution and social status.

What makes the Clonerkin rath quietly interesting is the absence of any visible entrance or internal features. Most ringforts preserve at least a hint of a gap or causeway that marks where people once moved in and out; here, nothing of the kind has been identified. The site appears on the Ordnance Survey six-inch map of 1838, where it is marked with hachures, the conventional cartographic shorthand used by the OS surveyors to indicate an earthwork of some kind. That the surveyors noted it at all suggests it was already a legible presence in the landscape nearly two centuries ago, and the earthworks have evidently held their shape since.