It is a souterrain, one of the hand-built subterranean chambers that appear across early medieval Ireland, typically associated with nearby settlement sites and thought to have served as places of refuge, storage, or both. What makes this one quietly notable is its construction: the roof is formed from flat stone lintels laid horizontally across the passage walls, a technique that speaks to considerable effort and some engineering forethought on the part of whoever built it.

The structure has two openings, one facing north and one facing south, which is an unusual bilateral arrangement. Most souterrains have a single, often concealed entrance, so the presence of two opposing openings raises questions about how this one was used and by whom. The passage has suffered a partial collapse at some point, which is a common fate for these structures given that they rely entirely on the integrity of their stone lintels and dry-laid walls, with no mortar to compensate for settling ground or the weight of centuries of soil above.