Cahernamallaght, in County Mayo, contains the Irish word "cathair", referring to a stone-walled enclosure, typically of early medieval date, used to define and defend a settlement or farmstead. That the townland carries this name suggests the enclosure here was once prominent enough to anchor the identity of the surrounding landscape, even if the structure itself has since faded from general notice.

Stone enclosures of this type are found across the west of Ireland, particularly in areas where drystone building was the dominant tradition. They range from substantial ring-forts with thick defensive walls to more modest agricultural boundaries, and distinguishing between them often depends on surviving height, wall thickness, and associated features such as souterrains (underground stone-lined passages, likely used for storage or refuge) or internal building platforms. The "caher" element in a place-name is generally taken as a reliable indicator that a stone-walled structure of some antiquity once stood, or still stands, on or near the site. Mayo, with its exposed Atlantic terrain and long tradition of pastoral farming, has numerous examples, though many remain incompletely documented.