At a depth of just under a metre and a quarter, the hole dropped into a dry stone passage running north to south, its lintels, the flat capstones laid across the top of the walls, still intact and visible on either side of the opening. The passage itself measured only 0.44 metres high and roughly 0.58 metres wide at its base. Nobody could get inside.

Souterrains are underground stone-built passages or chambers associated with early medieval settlement in Ireland, typically constructed between the seventh and twelfth centuries and usually found within or close to ringforts. They served various purposes, most likely food storage, given their cool stable temperatures, and possibly refuge in times of danger. What makes this particular example of interest is the extreme narrowness of the passage. At those dimensions, it almost certainly represents a creepway, a deliberately constricted section of a souterrain designed to slow or stop an intruder, forcing anyone moving through it to crawl and making defence considerably easier for anyone waiting on the other side. The upper 0.6 metres of the opening, before reaching the stonework, proved to be topsoil and gravel overburden, which suggests the souterrain had remained sealed and undisturbed for a long time before the surface gave way.