The souterrain, a type of stone-lined underground passage or chamber built in early medieval Ireland, has since been sealed for safety reasons, and the ogham writing, an early Irish script carved as a series of notched lines along a stone's edge, remains out of reach. That it exists at all is known only because field notes from October of that year recorded the find in detail: a chamber partly natural and partly constructed, six feet high and five feet wide, with a large capping stone running across its roof.

The site itself is called Cahernead, or Cathair Néid in Irish, meaning the stone fort of a person named Néid. A cahir is a type of ringfort built from stone rather than earthen banks, and this one sits on the summit of a limestone outcrop in north Kerry, commanding a clear view of the surrounding land. Its enclosing wall is roughly five metres wide and stands about 1.3 metres on the interior face and 2.2 metres on the exterior, the difference in height reflecting the elevated ground level within. The interior spans 24 metres across in both directions and is scattered with mounds and hollows. Beyond the wall itself, the surrounding landscape carries the same uneven character, with circular depressions and additional mounded features suggesting that Cahernead was once a considerably larger settlement, not merely a defended enclosure but an occupied complex of some scale.

The sealed souterrain means that the ogham stone cannot be inspected, but the fort itself remains visible on its limestone summit, and the breadth of ancillary features around it rewards careful attention. The wall, though partially degraded, still conveys the original scale of the enclosure, and the concentration of earthworks outside it hints at how much activity once surrounded this single named fortification.