Ráth an Mhianaigh translates roughly as the ringfort of the mine, an unusually specific piece of naming in a landscape where most raths are identified by family lineage or colour or the shape of the ground. Whatever mining activity once gave this corner of north Kerry its identity has long since disappeared, leaving only the earthwork and its quietly puzzling place-name behind.

The site itself is a univallate rath, meaning a single-banked enclosure, a type of monument built in early medieval Ireland, roughly between the fifth and twelfth centuries, and used primarily as a farmstead or high-status residence. The enclosing bank here has an internal diameter of 36 metres and stands about 1.3 metres high on its outer face, dropping to 0.8 metres above the interior floor level. At its base the bank measures 5.3 metres wide. Running along much of the outer edge, from the north-east around through the east to the south-west, is an exterior fosse, the ditch that would originally have been dug to provide the earth for the bank itself. That fosse is roughly 2 metres wide and sits about 0.7 metres below the level of the surrounding land. Three gaps punctuate the bank at the east, south-west, and north-west, measuring 3 metres, 2.6 metres, and 2 metres respectively, though whether these represent original entrances or later breaks is not recorded. A modern field boundary has clipped the western side of the bank, cutting slightly into its profile. The site sits in the corner of a large field on boggy ground used for rough grazing, as documented in C. Toal's North Kerry Archaeological Survey, published in 1995.

The boggy surroundings mean the ground immediately around the rath can be soft underfoot, particularly in wetter months. The earthworks are clearly legible in the field, and the fosse, though shallow, is still visible across a wide arc of the circuit.