This is a cashel, a type of ringfort defined by its stone enclosure wall rather than the more common earthen bank, and what remains here is just enough to suggest the original structure: a subcircular raised area measuring approximately 45 metres north to south and 40 metres east to west, ringed by a tumbled wall that still reaches between 0.4 and 0.8 metres in height and between 1.8 and 2.6 metres in width at various points.

Ringforts were the dominant settlement form in early medieval Ireland, typically serving as enclosed farmsteads for a single family or small community. Stone-walled examples like this one, known as cashels, tend to appear where building stone was more readily available than elsewhere. The Cornadowagh site was already old enough to be called simply 'Fort' on the Ordnance Survey's six-inch map of 1837, one of the earliest systematic cartographic surveys of the Irish landscape, which recorded it as a circular enclosure. A site inspection in 1976 noted an external fosse, a defensive ditch running around the outside of the wall, though no trace of this feature can now be identified on the ground. The original entrance, which in comparable monuments often takes the form of a gap or causeway through the enclosing wall, is no longer recognisable either. What the intervening decades have added, more than anything, is vegetation: the monument is now so heavily overgrown with scrub that the underlying archaeology is effectively obscured from casual view.