The townland name itself offers a small clue: Tawnaghmore derives from the Irish An Tamhnach Mhór, meaning roughly "the great cultivated field" or "the great green spot", a term that in Irish placename tradition typically signals land that was cleared and worked at some point, often in the early medieval period. That a monument was recognised here at all suggests something survives above or below the ground worth marking on the archaeological record, even if the fuller details are not yet widely accessible.

Achill Island has an unusually dense concentration of archaeological remains for its size, ranging from megalithic court tombs and promontory forts to the remnants of lazy-bed cultivation ridges left by communities displaced during the nineteenth century. Keel itself sits along a broad strand on the island's southern coast, beneath the dramatic quartzite scree of Minaun. The surrounding townlands carry traces of continuous human activity stretching back thousands of years, and a site recorded in Tawnaghmore would fit into that longer pattern of occupation, however its specific character is eventually confirmed.