A souterrain is a man-made underground passage or chamber, typically dry-stone built and associated with early medieval ringforts, where they likely served for storage or refuge. This one, if it survives at all, leaves no visible trace on the surface.

The claim rests almost entirely on local memory. Writing in 1918, a researcher named O'Leary recorded that the inhabitants of the locality asserted the existence of the flagged chamber below ground. That phrasing is worth pausing on: not that the chamber had been excavated and documented, but that local people, at that point, were still passing on the knowledge of it. The ringfort itself, a roughly circular enclosure of earthen banks that would have defined a defended farmstead in early medieval Ireland, is a known site in the area. The souterrain associated with it, however, remains unconfirmed, its flagstones neither seen nor disproved.