The arrangement is unusual enough on its own terms: a souterrain, which is an underground passage or chamber constructed in the early medieval period, typically for storage or refuge, does not ordinarily terminate in a natural geological void. Here, whoever built the passages seems to have discovered the cave and incorporated it deliberately into the system, making it the final destination of a carefully engineered underground route.

The souterrain itself is a considerable piece of work. Its main passage, constructed with slightly corbelled drystone walls, runs for 9.6 metres before turning westward. At the turn, where the natural bedrock forms the southern wall, the passage opens up in height and width. Beyond a narrow lintelled creepway, barely half a metre wide and sixty centimetres high, a further passage continues westward to the cave entrance. The cave measures roughly 5.45 metres north to south and 6.3 metres east to west, with an uneven floor sloping down to the southeast. A narrower rock-cut passage extends from its western end into a small rectangular chamber, though an accumulation of earth now blocks any further entry. The cave is currently home to a colony of lesser horseshoe bats, Rhinolophus hipposideros, a species that favours undisturbed underground spaces. The human remains found here were recovered on two separate occasions: bones removed from the cave floor in 1991 were identified by C. Power of University College Cork as belonging to an adult of at least thirty years of age, while earlier finds in 1953 were sent to England by the Office of Public Works for inspection. Whether these bones represent deliberate burial, secondary deposition, or something else entirely remains an open question.