What survives at Carrowholla is a rath, the Irish term for a ringfort, a type of enclosed farmstead typically built between roughly 500 and 1000 AD and once so common across the Irish countryside that tens of thousands of examples are known. This one is circular, roughly 24 metres in diameter, and its defining features follow the standard pattern: an inner scarp, a fosse (a cut or dug ditch running between the internal and external earthworks), and an outer bank.

The site is poorly preserved, which is itself a kind of record. The outer bank can still be read from the south-east around to the north-west, but from the south-west northward it has been absorbed into a later field boundary, the practical needs of agricultural land management quietly overwriting the earlier enclosure. That layering is common in the Irish landscape, where medieval and post-medieval field systems frequently followed, reused, or simply buried the edges of older ones. The hillock setting is worth noting too: raths were often placed on slightly elevated ground even within otherwise flat or waterlogged terrain, combining a degree of natural drainage with a modest commanding position over the surrounding land.