It is modest in scale, roughly eighteen metres across, and its enclosing bank barely rises half a metre above the interior ground level. Yet that low ring of earth, with its accompanying outer ditch, is the signature of a rath, the most common monument type in the Irish countryside, and this particular example survives in uncultivated mountain terrain that has kept it largely intact while similar sites elsewhere were ploughed or built over across the centuries.

Raths, sometimes called ringforts, were typically farmstead enclosures built during the early medieval period, roughly between the fifth and twelfth centuries, though the form persisted in some areas beyond that range. A family or small farming community would have lived within such an enclosure, using the bank and fosse, the shallow external ditch, as much for defining territory and managing livestock as for any serious defence. The Frankfort example, recorded by Denis Power and uploaded to the national survey in August 2011, has an external fosse measuring roughly thirty-five centimetres deep and ninety centimetres wide, figures that speak to a modest, functional construction rather than a heavily fortified one. The bank stands at the same height both internally and externally, which suggests the material was dug from the fosse and piled inward, a straightforward technique common across hundreds of comparable sites.

Reaching the site requires crossing uncultivated upland ground, so sturdy footwear and an awareness of the terrain are sensible precautions. The north-facing aspect means the slope can hold moisture and the vegetation is dense; the heather and gorse that blanket the interior and much of the bank make the earthwork easier to feel underfoot than to read visually from a distance. Late summer, when heather is in flower, makes the hillside more navigable in terms of colour contrast, though it does little to reveal the underlying archaeology. What a careful visitor will notice, walking the perimeter, is the subtle change in ground level as the bank rises and then falls away to the outer ditch, a gentle but legible trace of a settlement that has otherwise left nothing above the surface.