This rath at Rathduane is one of that trio, sitting on a gentle north-facing slope with a clear prospect over the river below. A ringfort, to use the general term, is a roughly circular enclosure defined by an earthen bank and, sometimes, an external ditch, typically dating from the early medieval period in Ireland and associated with farmsteads or settlement sites of relatively modest status. This one is univallate, meaning it has a single enclosing bank rather than the multiple concentric rings found at more elaborate examples.

The enclosure itself is nearly circular, measuring around thirty metres north to south and just under twenty-nine metres east to west. The internal face of the earthen bank still stands to about 1.3 metres in height, and there is a gap of roughly 1.9 metres on the east-south-east side, which would have served as the original entrance. The site appears on Ordnance Survey six-inch maps from 1842, 1904, and 1938, each time recorded as a univallate circular enclosure, which gives some sense of how slowly change comes to features like this. A note by Broker in 1937 described it as lying in a field locally known as "fort field" and being enclosed by a double fence, with the monument itself partially levelled at that point. Today the interior and the bank are partially overgrown with trees, which both obscures and, in a quiet way, preserves what remains. The alignment of this fort with its two neighbours along the south bank of the Blackwater invites the obvious question of whether the positioning was deliberate, perhaps marking out territorial boundaries or connected farmsteads, though the notes do not resolve that question.