A souterrain is an artificial underground structure, typically built during the early medieval period, consisting of one or more chambers or tunnels constructed from dry-laid stone and then buried. They are found across Ireland in considerable numbers, and their exact purpose remains a matter of some debate among archaeologists, with theories ranging from cold storage for dairy produce to places of refuge during raids.

The example at Gortnahurra carries no detailed published history at present. Its location in Mayo places it within a county that contains a notable concentration of early medieval activity, where ringforts, early ecclesiastical sites, and associated underground structures were once features of a farming landscape that has since changed almost beyond recognition. The souterrain would likely have been associated with a nearby settlement, possibly a ringfort, the circular earthen or stone enclosures that served as the homesteads of early medieval farmers and landowners throughout Ireland. Without further detail, the specific dimensions, construction technique, and condition of this particular example remain unconfirmed.