Most of the roughly thirty thousand ringforts surviving across Ireland consist of a single enclosing bank and ditch, but this one in West Cork is a bivallate example, meaning it is defended by two concentric earthen banks with a fosse, or ditch, between them, and a further external fosse beyond the outer bank. That degree of effort in construction, repeated around a roughly circular interior measuring only about thirty metres across, suggests the enclosed space and whoever occupied it were considered worth protecting.

The earthworks at Lissacaha are reasonably well preserved along much of their circuit. The inner bank still stands to an internal height of around 2.6 metres across its northern arc, and the outer bank reaches approximately 2.5 metres along its own better-preserved stretches. Both have suffered some levelling, particularly toward the south and east, where later agricultural activity has reduced sections to low, narrow replacements. The entrance, facing roughly east-southeast and about 3.5 metres wide, is partly flanked by a triangular area formed where the levelled eastern portion of the outer bank once stood. A berm, the flat shelf of ground left between an earthen bank and the edge of its associated ditch, runs along the inner face of the outer bank for a substantial stretch to the north. Perhaps most intriguing is what lies beneath the surface: near the centre of the raised interior is a souterrain, an underground stone-lined passage of the kind commonly associated with early medieval settlement in Ireland, likely used for storage or as a place of refuge. The interior itself sits perceptibly higher than the surrounding pasture, a subtle but telling sign of long occupation and accumulated activity within the enclosure.