On the ground, what survives of this early medieval enclosure amounts to a curved arc of raised earth, roughly 44 metres long and barely 22 centimetres high, running east to west across a tilled slope at Knocknanuss in north Cork. The external ditch that once defined its boundary survives as a shallow depression, no more than 20 centimetres deep. The northern half of the site has been lost entirely to agricultural activity, and a field boundary once cut across the site on an east-west axis. What the ground obscures, however, an aerial photograph has partly restored: the circular shape of the original enclosure shows clearly as a cropmark, the buried fosse, a rock-cut or earthen ditch, leaving its trace in differential crop growth visible only from above.

When the researcher Bowman recorded the site in 1934, it was already described as a levelled single-ramparted fort with a diameter of around 50 yards, standing on land belonging to a J. Cronin. Ringforts, known in Irish as raths when formed by earthen banks, were typically farmsteads of the early medieval period, enclosing a dwelling and its associated outbuildings within a circular bank and ditch. They are among the most common archaeological monuments in Ireland, yet the one at Knocknanuss has been reduced to little more than a faint swell in a ploughed field, its plan legible only to those who know where to look, and at what angle of light or season of growth.