The closure is a matter of safety rather than secrecy, but the effect is the same: one of the more intriguing finds from mid-twentieth-century Kerry archaeology remains effectively out of reach.

The site sits atop a limestone outcrop at Cahernead, a place whose Irish name, Cathair Néid, translates roughly as the stone fort of Néid, a personal name now otherwise lost to time. The fort itself is a circular univallate cahir, meaning a single-walled dry-stone enclosure of the kind built across early medieval Ireland as a defended farmstead or seat of local authority. What makes Cahernead more than a typical example is the scale of activity that seems to surround it: the land encircling the walls is scattered with depressions, circular features, and mounds suggesting a substantial and long-occupied settlement. The underground element came to wider attention not through formal excavation but through accident. According to Kerry Field Notes dated 6 October 1945, quarrying in the area broke into a large souterrain, the type of stone-lined underground passage or chamber built during the early medieval period, often for storage or refuge. This one was partly natural and partly constructed, measuring six feet high and five feet wide, with a substantial capping stone running across the centre of the roof. It was on that capping stone that ogham writing was found. Ogham is an early Irish script, typically carved as a series of notched lines along a central stemline, most often used to record personal names and found on standing stones across Munster. Its presence on a structural element deep inside a souterrain is an unusual circumstance.

The entire souterrain system has since been closed for safety reasons, and the two large stones that now mark its position in the north-east sector of the fort are as close as a visitor is likely to get. The ogham stone itself remains underground, unexamined since that quarrying accident more than seventy years ago.