These structures were typically constructed beneath or beside settlements, and their purpose has long been debated; cold storage, refuge, ritual use, and simple concealment have all been proposed at various times, often in combination depending on the site.

Slievemore itself carries an extraordinary density of human history. The mountain's southern flank is home to the Slievemore Deserted Village, a long street of roofless stone cottages abandoned in the wake of the Great Famine, though the settlement's origins reach back much further. The broader landscape contains megalithic tombs, field systems, and traces of activity spanning several thousand years, which makes the presence of a souterrain here entirely consistent with the pattern of long, layered occupation that characterises this part of Achill. Souterrains in Ireland date most commonly to the early medieval period, roughly the sixth to the twelfth centuries, and are frequently found in association with ringforts or early ecclesiastical sites.

Beyond its location on Slievemore, the specific details of this particular souterrain, its dimensions, its current condition, and its precise relationship to any surrounding features, remain to be fully documented in the public record. What is clear is that it sits within one of the more archaeologically concentrated mountain landscapes in the west of Ireland, where almost any walk across the hillside brings the past underfoot.