The enclosure at Ballyryan measures roughly 26 metres east to west and 25 metres north to south, a subcircular form that was already difficult to read when inspectors visited in 1998 and found the wall so buried in vegetation that neither its height nor its width could be reliably measured. What survives is lowest along the stretch from the north-east to the south, giving the whole structure a lopsided, half-dissolved quality.

Inside, the grass-covered ground slopes gently eastward, and in the north-east quadrant there are traces of a hut site, the kind of small stone-built shelter associated with early medieval settlement in the west of Ireland. Near the centre of the interior, slightly to the west-north-west, sits a low mound about two metres across and half a metre high, its purpose unrecorded. More conspicuous is a large glacial erratic positioned against the inner face of the western wall, one of those boulders deposited by retreating ice sheets thousands of years before anyone thought to build around it. Further erratics lie outside the enclosure to the north-north-east, suggesting the builders worked around, and perhaps with, a landscape already dotted with substantial loose stone. Against the outer northern and north-north-eastern edges, modern stone pens have been added over time, farmers making practical use of an old boundary without particular concern for what it once was. Around 98 metres to the east, a cashel and souterrain, the cashel being a stone-walled ringfort and the souterrain an underground passage typically used for storage or refuge, indicate that this hillock was part of a broader pattern of early settlement rather than an isolated curiosity.