A souterrain is an underground stone-built passage or chamber, typically associated with early medieval settlement in Ireland, and often used for storage or refuge. This one managed to remain hidden until the 1880s, when local accounts describe slabs being lifted from the ground to reveal not one but six chambers underneath.

The discovery appears to have been made around that decade, though no formal excavation seems to have taken place. Six chambers is a considerable number; most known souterrains consist of one or two passages, sometimes with a side chamber or creep connecting them. What was found inside, or what condition the structure was in, went unrecorded in any detail that survives. The decision to infill the site followed shortly after the slabs were lifted, and the underground complex was sealed once more. No visible surface feature now marks the location.