A ringfort, or rath, is a roughly circular enclosure dating from the early medieval period, typically built as a farmstead and defined by one or more earthen banks and ditches. This one in Ballynalynagh, County Mayo, has been reduced over the centuries to little more than a low swelling in the pasture, its banks worn and broken, yet it has held its name across nearly two centuries of mapping and almost certainly for far longer before that.

The rath sits on a gentle rise in rolling farmland, measuring roughly 24 metres east to west and just over 25 metres north to south. Its enclosing bank, built of earth and stone, survives to an external height of about 0.8 metres on the southern side, though to the west and east it has degraded into little more than a broad, shallow scarp. A field fence running east to west cuts directly along its northern edge, and another short section of fencing clips across the bank to the north-east, the ordinary business of agricultural land management slowly absorbing what came before it. The name Rathmoragha appears on Ordnance Survey six-inch maps from both 1838 and 1922, suggesting that local knowledge of the site, and whatever association the name carries, remained alive well into the twentieth century.

One detail lifts the site beyond the ordinary: a second ringfort stands on a knoll approximately 195 metres to the north-west, clearly visible from Rathmoragha's low rise. Paired or clustered ringforts are not unknown in the Irish landscape, and seeing two in such close proximity raises the kind of questions that the physical remains alone cannot answer, about the families or communities who built them, and what relationship, cooperative or otherwise, existed between them.