A rath, in the Irish Early Medieval tradition, was a roughly circular enclosure defined by an earthen bank and ditch, used as a farmstead or residence of some local standing. This one, on the southwestern slopes of Knocknahoran at Baile Na Buaile, is a univallate example, meaning it has a single such enclosure rather than the concentric rings found at more elaborate sites.

The interior measures about 24.5 metres across, and the earthen bank, reinforced with stone, still stands up to 2.5 metres high on its outer face, though only about a metre on the inside, where the material has slipped over time. There is evidence that this inner face was once neatly lined with drystone walling; the second edition of the Ordnance Survey map records its inner edge as a continuous solid line, a convention that typically indicates a faced stone surface. That walling has since collapsed entirely, and the overgrown interior is scattered with loose stones, the slow residue of that long deterioration. The external fosse, a shallow ditch running around the outside of the bank, can still be traced around much of the eastern half of the site. It is roughly two and a half metres wide and less than a metre deep, with some surviving revetment stonework along its inner edge. On the western side, where the road boundary wall crowds in close, the fosse has vanished, most likely displaced or buried during road improvements. The original entrance, on the eastern side, is just under one and a half metres wide, and a single low course of drystone masonry survives along its southern edge. These details were documented as part of the Dingle Peninsula archaeological survey published by J. Cuppage in 1986.