The site at Baile An Ásaigh contains what is believed to be a souterrain, an underground stone-lined tunnel or chamber typically built during the early medieval period in Ireland, often associated with storage, refuge, or ritual use. What makes this particular example quietly interesting is how tentative its presence remains: its location is inferred not from excavation but from a low surface ridge extending roughly nine metres to the west-south-west of the enclosing earthwork above it.

The souterrain sits within, or close to, a univallate rath, meaning a circular earthen enclosure defended by a single bank and ditch. These raths were the farmsteads of early medieval Ireland, scattered across the landscape in their thousands, and it was common practice to cut a souterrain beneath or beside them. The ridge that hints at the buried passage was identified through local knowledge rather than any formal investigation, which places it in a long tradition of features that survive in folk memory and surface topography long after the structures themselves have become invisible. The archaeological record for the site draws on J. Cuppage's 1986 survey of the Dingle Peninsula, Corca Dhuibhne, one of the more methodical attempts to document the dense concentration of prehistoric and early medieval monuments in that part of Kerry.