The structure is a souterrain, an underground passage or chamber typically built during the early medieval period in Ireland, most often associated with nearby settlements and used for storage, refuge, or both. What makes this one quietly arresting is its visibility: rather than being entirely buried and forgotten, a stretch of passage some 3.85 metres long and less than a metre wide can still be traced at the surface, surrounded by a low cairn of accumulated stone roughly six metres across.

The cairn itself, along with two clearance cairns nearby, suggests a landscape that was once actively worked and managed, the stones gathered and piled as people cleared ground around them. The souterrain sits approximately fifty metres north of a rath, the circular earthwork enclosure that was the standard form of rural farmstead in early medieval Ireland. This proximity is typical: souterrains were commonly dug within or immediately beside raths, connected to the daily life of whoever lived inside the enclosure's banks and ditches. Whether the underground passage here was reached from within the rath or from the slope above it is not recorded, but the relationship between the two structures is almost certainly not coincidental. The whole complex now lies within a coniferous plantation on the hill, roughly two hundred metres north of an east-west stream that cuts across the lower ground.