The hut itself is modest enough: a low bank of earth and stone, roughly half a metre high and a metre wide, enclosing an internal space of about 4.5 metres across, open on its south-eastern side where an old field-wall passes nearby. What makes the site worth pausing over is what lies beneath it. Tucked against the hut's south-western exterior, close to a large boulder that partly covers the entrance, is the opening to a souterrain, an underground passage system cut into the earth and used, typically in early medieval Ireland, for storage or refuge.

This particular souterrain runs through three chambers connected by narrow creepways, the low crawl-through openings, rarely more than 65 centimetres high, that linked one underground space to the next. The first chamber, roughly circular and cut from the earth, measures about 2.35 metres across and just over a metre in height; a section of drystone walling on its north-western side may mark where the chamber was originally excavated from a now-blocked construction shaft. From there, a passage leads into a second chamber, longer and wider, its lower walls reinforced with large stone slabs and a ventilation shaft still traceable at its northern end. A further creepway in the south wall of that chamber opens into a third, slightly lower space aligned north-east to south-west, running another 3.1 metres before an accumulation of collapsed fill brings progress to a halt. The whole system is oriented carefully, its chambers offset from one another in a way that would have made navigation difficult for anyone unfamiliar with the layout, which may well have been the point.