What lies beneath, or more precisely what once lay beneath, is likely a souterrain, an underground stone-lined passage or chamber of the kind built throughout early medieval Ireland, typically for storage or as a place of refuge. This one, at Knockagarry in North Cork, appears to have collapsed in on itself at some point, leaving only the tell-tale hollow and that protruding slab as evidence of what was once below ground.

What makes the site particularly interesting is its setting. The souterrain sits within the eastern half of a moated site, a type of monument more associated with the Anglo-Norman period than with the native Irish tradition of souterrain construction. Moated sites were generally enclosed farmsteads, their rectangular platforms surrounded by a water-filled or wet ditch, and they appear across Ireland largely as a result of medieval colonisation following the twelfth-century Norman arrival. Finding a souterrain within such an enclosure raises quiet questions about the sequence of activity on the ground, whether an earlier underground feature was later incorporated into a new landscape, or whether the two belong to overlapping phases of use. The site carries a preservation order, recognising its significance as a layered piece of the North Cork archaeological record.