A souterrain, which is a stone-lined subterranean chamber or tunnel typically associated with early medieval settlement in Ireland, often used for storage or refuge, lies here without any visible trace at the surface. The vegetation has simply closed over it.

The souterrain sits within a ringfort, the kind of roughly circular enclosure, defined by earthen banks or stone walls, that served as a farmstead during the early medieval period, broadly from around the fifth to the twelfth century. Ringforts are common across Ireland, with thousands recorded, but each one represents a specific household or small community, and the souterrains associated with them are individually built features, not generic additions. This one occupies the western side of the enclosure at Ahalisky, though the overgrowth that now conceals it makes any precise sense of its extent or character difficult to establish from the surface alone.