A low rise on the east side of a field boundary, possibly tracing the arc of a bank that once defined a circular enclosure roughly thirty metres across. Most visitors would walk straight past it.

Ringforts, known in Irish as raths, were the most common form of rural settlement in early medieval Ireland, typically consisting of a circular area enclosed by one or more earthen banks and ditches. They served as farmsteads, home to a family and their livestock. The one at Ballynaboul, on a north-facing slope in County Cork, was already being mapped as a recognisable earthwork when the Ordnance Survey recorded it on their six-inch sheets in 1842. At that point it appeared as a hachured roughly circular enclosure, the hachure marks indicating the slope and definition of the surrounding bank. Somewhere between that survey and the present, the enclosure was levelled, most likely through agricultural activity. A field boundary was cut through the interior, clipping just inside the south-western bank, and that boundary line now bisects what little survives. The low rise to the north-west, sitting on the east side of that boundary, may preserve the faintest memory of the original circuit.