A souterrain is an underground stone-lined passage or chamber, typically constructed during the early medieval period in Ireland, used variously for storage, refuge, or both. They are not especially rare in Cork, but most betray at least some hint of themselves, a slight depression in the ground, a scatter of displaced stone, a hollow that catches the eye. This one offers nothing at all.

What the site does preserve, in the surrounding landscape, is a suggestive arrangement of enclosures. Two circular enclosures lie close by, one approximately fifty metres to the south-west and another approximately fifty metres to the north. Circular enclosures of this kind are often the footprints of early medieval farmsteads, the raised or ditched boundaries of a rath or ringfort within which a family would have lived and kept livestock. The proximity of a souterrain to such enclosures is entirely consistent with how these underground features were used; they were frequently dug into or beside the banks of ringforts, functioning as concealed stores or bolt-holes. Whether the souterrain at Ballyvorisheen was physically connected to either of these enclosures is not recorded, but their clustering in the same small area suggests a settlement of some coherence once occupied this ground.