That single discovery was enough to suggest the presence of a souterrain, one of the underground stone-lined passages that early medieval Irish communities built alongside their settlements, most likely for cold storage, refuge, or both. The hole was never fully excavated, at least not on record, which means this site exists in a peculiar state of suspension: noted, suspected, but not confirmed.

The ringfort itself, catalogued separately, anchors the find in a recognisable pattern. Souterrains are frequently discovered in close proximity to ringforts across Ireland, and their association with these circular enclosed settlements, which were in common use roughly between the seventh and twelfth centuries, is well established. The Carrigaline example came to light through O'Leary, whose published account recorded the ploughman's encounter with the void near the lios. Beyond that circumstantial detail, the record is thin. No dimensions, no date of discovery, no follow-up investigation is documented.