A souterrain is an underground stone-built passage or chamber, typically associated with early medieval ringforts and used variously for storage, refuge, or both. This one sits on the northern side of a ringfort that has since been levelled, leaving no visible trace at ground level. The fort is gone, the entrance is gone, and the souterrain itself has effectively vanished back into the earth.

What little is known comes from local memory rather than formal excavation. At some point in the past, at least one stone-built chamber was entered, though by whom and when is unrecorded. The people who knew about it noted, with a certain vagueness that is itself telling, that there could have been more chambers beyond it. Whether the passage was explored out of curiosity, stumbled upon during agricultural work, or deliberately investigated is not known. The ringfort to which it once belonged has been assigned the reference CO029-06701, though the fort itself has been so thoroughly levelled as to leave nothing for a visitor to stand beside or measure.

What this site represents, in a quiet way, is the ordinary fate of a great many early medieval features in the Irish landscape. The ringfort and its underground companion survived for perhaps a thousand years before the ground above them was put to other uses. Now the souterrain persists only in local recollection and a brief inventory entry, a stone room under a field that someone once crawled into and emerged from, and whose full extent was never properly known.