Known in Irish as Cathair na nAcraí, or Cahernanackree, the site is a bivallate cashel, meaning it was enclosed by two concentric defensive walls or banks rather than the single ring more commonly associated with Irish ringforts. That layered defensive architecture implies a settlement of some social consequence, though what survives today is heavily reduced, and much of what was once visible has either collapsed or been buried beneath centuries of erosion and neglect.

The cashel has an internal diameter of roughly 28 metres. Its inner wall, once a substantial drystone construction, has been reduced to a spread of stone collapse reaching about 1.5 metres high in places. Between the inner wall and the outer earthen bank runs a fosse, a defensive ditch, which varies between 3 and 9 metres wide and contains a third, shorter bank along its western sector. At the centre of the enclosure stands a rectangular foundation, nearly 10 metres long and built in drystone, whose walls survive to around 0.75 metres. Partially hidden within the stone collapse to its west is an accidental opening into a souterrain, an underground stone-lined chamber used in early medieval Ireland typically for storage or refuge. The chamber, roofed with five flat slabs, measures roughly 2.2 by 1.5 metres and is only 0.7 metres high. When the site was examined in 1940, further chambers and passages led off from this point, along with a circular hut, a triangular hut, two rectangular huts, and a series of roughly seven shallow circular depressions along the south-western interior. A possible stone mining hammer was found in one of the chambers. These additional features are no longer accessible. J. Cuppage documented the site in the 1986 Dingle Peninsula archaeological survey, and that account remains the principal record of what the cashel once contained in greater detail.