These structures were constructed using dry-stone walling and large capstones, and are found in considerable numbers across Ireland, though their precise function is still debated. Most archaeologists believe they served as cold-storage cellars, refuges, or places of concealment, often associated with a rath or ringfort on the surface above. The example at Rinbrack is recorded as a monument in its own right, which suggests its presence was notable enough to warrant formal documentation.

Souterrains in the west of Ireland occupy a quietly significant place in the early medieval landscape. Mayo has a reasonable distribution of them, often tucked beneath or beside the earthen banks of ringforts that were once the farmsteads of free farmers. The underground chambers were carefully engineered, sometimes incorporating low creep-holes between sections that would slow down any intruder who did not know the layout. The effort involved in their construction points to communities with both the resources and the motivation to build lasting, hidden infrastructure into the land itself. Beyond its county and townland designation, the specific details of this particular souterrain, its dimensions, its current condition, and its relationship to any above-ground features, are not yet in the public record.