The ringfort at Curraghavaddra sits on a south-south-east-facing slope, its earthen bank curving around a circular enclosure just over twenty-two metres across, with a fosse, or defensive ditch, running around the outside. What is unusual here is not the structure itself, common enough across Ireland, but its position: placed so close to the cliff edge that the sea has already won part of the argument. The north-north-west side of the enclosure has been lost to erosion, leaving the bank incomplete, a slow collapse that has been going on for longer than anyone recorded.

Ringforts, known in Irish as raths when formed from earthen banks rather than stone, were the standard form of enclosed farmstead in early medieval Ireland, roughly the fifth to the twelfth centuries. Thousands survive across the country in varying states of preservation. The one at Curraghavaddra follows the familiar pattern: a raised earthen bank, here standing to over two metres in height along its surviving arc from the north-east around to the west, with a gap to the south-east that would have served as the entrance, measuring just under two metres wide. Whether the builder was drawn by the view, the drainage of the slope, or some more practical consideration long since forgotten, the effect today is a structure that reads as both deliberate and precarious, its southern arc still solid in pasture while its northern edge has crumbled away into the bay below.