The souterrain, a type of underground stone-built passage or chamber associated with early medieval settlement in Ireland, was discovered in 1969 and subsequently infilled. Today there is no visible surface trace of it whatsoever, which places it in a particular category of archaeological site: documented, measured, and then effectively returned to invisibility.

What was recorded before infilling describes a single subrectangular chamber, stone built and roofed with capstones, two of which were still in position at the time of discovery. In the north-east corner there was a stone-built creepway, the narrow connecting passage typical of souterrain construction, which allowed movement between chambers or sections of the structure. The scholar McCarthy, writing in 1977, offered an alternative interpretation of this feature, suggesting it may not have functioned as a passage at all but rather as a construction shaft, the opening through which the builders worked as they assembled the chamber below ground. It is a small but telling disagreement. Whether the creepway was ever meant to be crawled through by a living person, or whether it was simply a practical necessity of the building process later sealed off, changes how one imagines the souterrain being used. Such structures are generally associated with food storage, refuge, or both, and their interiors were designed to be difficult to navigate, low-ceilinged and deliberately awkward for anyone unfamiliar with the layout.