These structures were usually constructed by roofing over a trench with large lintels and then covering the whole with earth, leaving little or nothing visible at the surface. That near-invisibility is part of what makes them quietly remarkable: a community's deliberate effort to leave something functional hidden just below the ground.

Souterrains are found across Ireland in considerable numbers, most often associated with early medieval settlement sites such as raths or cashels, the enclosed farmsteads that were the dominant form of rural habitation from roughly the sixth to the twelfth centuries. Their precise purposes are still debated, though cool storage for dairy produce and short-term refuge during raids are the explanations most commonly advanced. The one at Rinbrack is recorded as a monument, placing it within a broader pattern of such features across Connacht, where the landscape holds many traces of that period of settlement, most of them unannounced and easy to pass without noticing.