It is a souterrain, a type of man-made subterranean structure built during the early medieval period in Ireland, typically consisting of one or more stone-lined chambers connected by low, narrow passages. The purpose of these structures has been debated for generations; they may have served as cool storage for food, as places of refuge during raids, or as both at different times. Whatever its original function, the one at Gorteen has, for now, slipped quietly past the record-keepers.

The archaeological record for this site remains sparse, which is itself a kind of historical fact. Souterrains are found across Ireland in considerable numbers, often associated with early Christian ringforts and settlement sites, and many were constructed between roughly the seventh and twelfth centuries. Their builders favoured dry-stone corbelling techniques, sometimes achieving remarkable spans without mortar. That a souterrain exists at Gorteen places the townland within a wider pattern of early medieval habitation in Connacht, a region where such structures, though less densely distributed than in Munster or Ulster, do appear in association with enclosed farmsteads and small monastic sites. The specifics of this particular example, its dimensions, its condition, its relationship to any surface features nearby, remain unconfirmed in the public domain.