The souterrain, as these subterranean stone-lined passages and chambers are known, is now entirely invisible at ground level, its mouth sealed, its slab roof undisturbed in the dark below.

The structure sat within a rath, the type of enclosed circular farmstead, defined by an earthen bank and ditch, that was built across Ireland in the early medieval period and remained in use for centuries. Raths are common across the Kerry landscape, but the presence of a souterrain within one is always a detail worth pausing over. These underground spaces served various purposes, among them storage, refuge, and possibly ventilation for perishables, and they were typically built with considerable care, their roofs formed from large flat slabs laid across corbelled or upright stone walls. At Lissyclearig, local knowledge preserved the memory of this one long after the entrance was blocked: stone steps, a descent, a chamber overhead with slabs. The specifics were recorded, but by the time they were, the access was already gone.