The word cashel, from the Irish caiseal, refers to a ringfort built in stone rather than earth, a circular enclosure whose curving wall once marked the boundary of a single farmstead or the seat of a local lord. These structures were built mainly between the fifth and twelfth centuries, and thousands survive across Ireland in varying states of preservation, though many have been robbed out over the centuries for convenient building material.

Brodullagh itself is a small townland in Mayo, a county where the Atlantic weather and the rocky terrain have shaped settlement patterns since the earliest periods of human activity. Stone cashels are particularly associated with areas where rock was more readily available than the soil needed to construct an earthen rath, and the west of Ireland has a notable concentration of them. The specific history of this example, including any details of its construction, its dimensions, or the people who once lived within its walls, remains to be documented in any publicly accessible form.