What survives is still legible as a monument: a circular enclosure roughly 32 metres across, its earthen bank rising nearly two metres on the exterior where it faces west and south-west, with a shallow external fosse, a ditch dug around the outside of the bank, accompanying it, and a second outer bank still standing to about 0.9 metres on the south-eastern side. The interior has been deliberately raised on the southern side to level off the ground within, compensating for the gentle south-westerly slope of the hillside.

Ringforts, known in Irish as raths when constructed from earth, were the most common form of rural settlement in early medieval Ireland, typically enclosing a farmstead and its associated buildings. This one at Knockastuckane sits within a small cluster of five such forts recorded on land belonging to a Mr Leader, noted by a researcher named Bowman in 1934. The group, of which this is one, were described at that time as levelled or partially levelled, suggesting that agricultural activity had already taken a toll on them before the quarrying compounded the damage here. Five single-ramparted forts within one landholding is an unusual concentration, and hints at a landscape that was once densely settled during the early medieval period, even if the surface evidence has been progressively worn away.