Discovered in November 1985, this souterrain, an underground structure of the early medieval period typically used for storage, refuge, or both, consists of four chambers linked by narrow creepways, with a small annexe branching off the second chamber. The largest chamber runs to 3.2 metres in length, but none exceeds a metre in height, which tells you something about how a person would have moved through it, and perhaps about the urgency with which it might have been used.

The construction details are quietly revealing. Each of the four chambers contained what are known as construction shafts, vertical openings used during the building process to remove spoil and lower materials underground before being sealed over. R. M. Cleary, who communicated details of the site, suggested that the original entrance lay in the north wall of the fourth chamber, an unusual position that hints at deliberate concealment or a specific relationship with whatever structure stood above ground. That structure, while no longer visible, may be inferred from the disturbed soil overlying the souterrain, which contained dark, peaty lenses consistent with long-term habitation. A spindle whorl, a small weight used to spin thread, was recovered from the same disturbed layer. It is a modest object, but a grounding one: it places a person, most likely a woman engaged in textile work, somewhere very close to this spot, probably during the early medieval centuries when souterrains were in common use across Ireland.