This is a souterrain, an underground passage or chamber type found across early medieval Ireland, typically associated with nearby settlement and used variously for storage, refuge, or ventilation of associated structures. What makes this one quietly odd is its possible origin: rather than being dug from scratch, the builders may have exploited a natural fissure in the rock, following a ready-made void and supplementing it with their own stonework.

The passage, first recorded by J. Cuppage in the 1986 Corca Dhuibhne archaeological survey of the Dingle Peninsula, runs roughly five metres in total. It enters from the north, travels south for about two metres, then veers slightly south-west for the rest of its length. Upright slabs form the side walls, in places topped with one or two dry-stone courses, and flat slabs roof the whole thing. At its widest it reaches just under a metre across, and at its highest around seventy centimetres, though both dimensions shrink steadily towards the inner end, which is now too small to enter. The entrance itself is built from the outermost sidestones and a single roofing slab, above which four or five loosely stacked stones sit on the surface. These appear to serve no structural purpose, which lends the entrance a slightly provisional look, as though the builders themselves were uncertain what the feature needed.

The site looks out over the broad plain drained by the Feohanagh River, a considerable sweep of low ground that would have been visible to whoever used this hillside. That long sightline, combined with the passage's hidden, inward-facing construction, gives the place an atmosphere that is difficult to explain by function alone.