On the south-facing slope of a broad east-west ridge at Ballyportry, a large subcircular enclosure roughly 69 metres across stretches across pasture land, its edges a palimpsest of different periods pressing against one another: an ancient cashel, a drystone wall built over it, a later field wall collapsed across that, and a farm track running straight through the middle as if none of it were there.

A cashel is a roughly circular stone-walled enclosure, typically of early medieval origin, built to demarcate a farmstead or settlement. The Ballyportry example is defined along its southern arc partly by what may be a natural rock scarp rather than wholly constructed masonry, which makes the boundary between deliberate enclosure and landscape feature productively ambiguous. The southern edge of this scarp overlooks a cluster of derelict houses dating to the eighteenth or nineteenth century, suggesting the site continued to anchor human activity long after its original function had been forgotten or repurposed. A rectangular enclosure sits within the north-east quadrant of the interior, abutting the perimeter wall, its dimensions roughly 22 by 19 metres internally; it is defined on the west by collapsed stone and on the south by a low earthen scarp. The whole site was recorded on the first edition of the Ordnance Survey six-inch map in 1842, and was hachured again on the twenty-five-inch plan of 1897 and the Cassini edition of 1920, meaning surveyors across at least three generations noticed it was something worth marking, even if none labelled it with particular precision.

The interior is heavily overgrown, and the stratigraphy of the boundaries, where one wall overlies another overlies a possible bank, rewards careful attention rather than a quick glance. The grass-covered spread of stones to the east of the farm track, roughly ten metres wide and low to the ground, is easy to walk past without registering what it might represent. Wide views open to the south from the ridge, which may explain why the site was placed here to begin with.