The enclosure, roughly 32 metres east to west and 26 metres north to south, belongs to that vast class of early medieval farmsteads known as ringforts or raths, earthen and stone enclosures that once housed farming families across Ireland, typically between the sixth and tenth centuries. What survives here is denuded and unassuming: the bank reaches only around 0.7 metres in external height, and much of its surface is covered in loose stones that may simply be the accumulated debris of generations of field clearance rather than original construction material.

Despite its modest appearance, the interior holds several features that suggest a more layered history. A large rock outcrop occupies the north-eastern quadrant, where loose stones are particularly concentrated, and at the centre of the enclosure there is a possible hut site, the traces of a structure where people once lived and worked. Perhaps most intriguing is the possible souterrain in the northern sector. A souterrain is an underground passage or chamber, usually constructed from stone, which in the early medieval period served variously for storage, refuge, or ventilation. Whether the Clashnagarrane example was ever properly built out, or remained only partially formed, is not clear from what survives above ground. A possible entrance gap through the bank on the south-eastern side hints at how the enclosure was originally approached, though the slope of the interior, which descends from east towards a break of slope in the west, would have shaped daily movement within it in ways that are now difficult to read.