It has simply been there, unannounced, while walkers pass above it heading up the headland.

A souterrain is a man-made underground structure, typically dry-stone built, associated with early medieval settlement in Ireland. They were used variously for storage, refuge, or as escape routes connected to nearby ringforts. This particular example is modest in scale but carefully made: the passage runs roughly east to west, stretches approximately 3.5 metres in length, and measures around 0.9 metres wide and 0.7 metres high, just large enough to move through on hands and knees. The walls corbel slightly inward toward the top, a technique where successive stone courses project a little further inward as they rise, narrowing the space before the roof lintels close it off. At least six of those lintels remain in place. Midway along the southern wall, a low creepway opens into the passage, a secondary crawl-through that in other souterrains typically connects chambers or provides a concealed exit. A small gap between two of the roofing slabs gives a glimpse into the interior without needing to enter.

The site lies on the south side of the trackway that ascends Bray Head, and anyone who knows to look for it can peer down through that aperture in the roof and see the drystone construction still holding together after more than a thousand years of Atlantic weather rolling in off the Kerry coast.