This is a cashel, a type of ringfort defined by a stone wall rather than an earthen bank, and what makes this particular example at Knockaunroe quietly interesting is how plainly its various layers of human intervention have been left visible rather than tidied away.

The cashel measures roughly 20 metres across internally, and its perimeter tells a different story depending on which direction you read it. The western to northern arc is defined by a stony bank some five metres wide and standing about 1.5 metres high, though a portion of this bulk appears to come not from original construction but from modern field-clearance spoil, with boulders piled onto whatever earlier structure remained. The north-eastern side is far more modest, a low bank only 0.3 to 0.5 metres high with some field stones scattered along it. The eastern to south-western stretch has been rebuilt entirely as a loose drystone wall, two metres wide and roughly a metre tall. The site was recorded on the first Ordnance Survey six-inch map of 1842 and again on the Cassini edition of 1920, both times marked with hachuring that indicated an enclosure of some kind, though it was catalogued simply as an 'Enclosure' in the Record of Monuments and Places as recently as 1996. Field walls that once radiated outward from the cashel to the east, south-west, and west have since been removed, and a cairn of cleared field stones sits just to the east, a reminder that the land around it has continued to be worked and reshaped long after whoever first built the cashel had gone.