Lacht air Iorrais, near An Geata Mór, translates roughly from the Irish as a grave mound, or burial cairn, on the Erris peninsula. The word lacht, used in Irish-language placenames, typically refers to a stone-covered grave or funerary cairn, often of early medieval or prehistoric origin. That such a name has stuck to this location across centuries of use suggests the feature was once visible and significant enough to anchor local memory and wayfinding.

The Erris region, a broad and largely boggy territory stretching across the northern shoulder of County Mayo, has long been one of the more sparsely documented parts of Ireland in archaeological terms, not because it lacks material, but because its remoteness slowed systematic survey work. The peninsula and its surroundings contain traces of habitation reaching back to the Neolithic period, and named burial sites in the landscape are often the last surviving echo of funerary traditions that predate the Christian era by millennia. A lacht of this kind would typically consist of a low cairn of stones, sometimes covering a cist grave or a simple pit burial, and in many cases barely distinguishable today from the surrounding rocky or boggy ground without careful inspection.