What makes the Coolrus example worth pausing over is the way it combines two distinct methods of defining its boundary: on the south-west to south side, the ground has simply been cut away into a scarped edge, a near-vertical drop of around one and a half metres, while on the southern to south-western arc the builders constructed a more conventional earthen bank with an external fosse, or ditch, separated from the bank by a level berm roughly 1.8 metres wide. The effect is a hybrid enclosure, part carved from the hillside, part built up from excavated material, and the combination suggests a community making practical use of whatever the local topography offered.

Ringforts, known in Irish as raths when defined primarily by earthworks rather than stone, were the dominant settlement form in early medieval Ireland, roughly from the fifth to the twelfth centuries. They typically enclosed a family farmstead and its outbuildings, with the bank and ditch serving less as serious military defences and more as a marker of status and a barrier against livestock straying or predators encroaching. The Coolrus fort is roughly circular, measuring approximately 42 metres on its south-west to north-east axis and just under 40 metres the other way, dimensions that fall within the typical range for a single-family enclosure of middling status. The site was recorded and compiled by Denis Power, with notes uploaded in August 2011.

The fort sits in working pasture, so access depends on the landowner and the season. The earthworks are most legible in low winter or early spring light, when grass is short and shadows pick out the relief of the bank and the slight hollow of the fosse. The north-west quadrant of the interior is noticeably raised above the rest of the enclosed area and covered in nettles, which often signals subsurface disturbance or the remains of a structure beneath; it is worth looking at carefully without disturbing anything. The scarped southern edge is the most visually immediate feature on approach, where the slope drops away cleanly and the ground level inside the enclosure suddenly announces itself.