A souterrain, to use the technical term, is an artificially constructed underground passageway or chamber, typically associated with early medieval Irish settlement and used for storage, refuge, or both. What makes this one quietly arresting is how it came to light: not through formal excavation, but through the sudden collapse of the ground itself, the earth simply giving way beneath a working farm.

When the collapse occurred, the passages were briefly exposed. They had been cut from stiff clay with rounded roofs, running approximately eight metres in a south-easterly direction, with further passages extending to the south-west. The construction method, cutting directly into firm subsoil rather than lining with stone, is a recognised variant in Cork souterrains, where suitable clay geology permits it. The site is also associated with a possible cashel, a type of stone-walled early medieval enclosure typically used to define and defend a farmstead, which suggests this underground structure may once have sat within or alongside a more substantial settlement. The entrance to the passages has since been closed up, and today the only surface evidence is a shallow depression, roughly half a metre deep, marking where the ground gave way.