The site is a rath, the Irish term for a ringfort, which was the standard form of enclosed farmstead used throughout early medieval Ireland, typically from around the fifth to the twelfth centuries. Thousands survive across the country in varying states of preservation, but this one in Oldcastletown has reached a point where the land itself seems to be absorbing it, the defining earthen bank heavily overgrown, the surrounding fosse, a defensive ditch, partly reduced to a shallow depression.

The enclosure is roughly circular, around forty-five metres in diameter, and sits on a natural rise, which would have given its original occupants both drainage and visibility across the surrounding ground. The bank survives to an internal height of about 1.25 metres along its northern to south-western arc, while elsewhere the boundary survives only as a scarp, a sloped edge in the ground rather than a raised mound. An external fosse, roughly half a metre deep, traces the perimeter from north around to the south-south-east. To the west, where the fosse has been ploughed or worn nearly flat, its path becomes legible only as a cropmark, a slight difference in how vegetation grows over buried features. The southern stretch of bank has been absorbed into a field fence, tying the ancient structure into the working geometry of the modern farm. A boreen, a narrow country lane, runs north to south just outside the fosse to the east. The interior is rough grass and thistles.