It is not on the Ordnance Survey maps of 1838 or 1920, though the 1920 edition does mark a feature labelled simply 'Cave' within it, which turns out to be a souterrain, an underground stone-lined passage or chamber typically associated with early medieval settlement in Ireland. The structure as a whole is something stranger: a natural hillock that has been deliberately scarped and shaped into a raised platform roughly 55 metres across, with a further ovoid mound, some 32 metres long and over two metres high, sitting on top of it. The effect is of a mound balanced on a platform, with a narrow walkway of clear ground, known as a berm, running around the base of the inner mound on most sides. From the flat oval summit, the land drops away steeply, and the views extend across rolling grassland to the south-west, west, and north, with an upland ridge visible to the north-east.

The site was first formally recorded by Knox in 1911, who noted that it bore a passing resemblance to a Norman motte and bailey, the characteristic earthwork fortification introduced to Ireland after the twelfth-century invasion, in which a raised mound sits beside or above a lower enclosed courtyard. Knox pulled back from that interpretation precisely because of the souterrain, which is set into the slumped western slope of the mound. Souterrains belong to a much earlier tradition, most commonly the early medieval period, and their presence here complicates any straightforward Norman reading. The competing possibilities are that the mound was once a form of rath, a ringfort-type enclosure common across early medieval Ireland, with the confined flat top serving as a living or working space, or that the mound itself is prehistoric in origin and was simply reused at a later date when the souterrain was added. A possible fosse, a defensive ditch, survives as a depression on the north-east side, separating the platform from the naturally rising ground beyond, though no such ditch runs around the rest of the monument. A slumped section of the platform edge at the north-west may once have been the formal entrance, with a narrow natural spur of the hillock extending some 35 metres to the north-north-west providing a kind of approach route up to the berm.