Its roughly circular interior measures around 27 metres across, enclosed by an earthen bank about a metre in height, with sections faced in stone, giving it a hybrid quality somewhere between a purely earthen construction and a more formal stone-built enclosure. The entrance gap, at just under three metres wide, opens to the south-west, which is a common enough orientation in Irish ringforts and likely reflects both practical considerations around prevailing winds and the significance of the south-west in early medieval Irish settlement patterns.

Ringforts, known variously as raths or cashels depending on whether their banks are earthen or stone-built, are among the most common archaeological monument types in Ireland, with tens of thousands recorded across the country. They functioned primarily as enclosed farmsteads during the early medieval period, roughly between the fifth and twelfth centuries, and the enclosing bank served as much as a marker of status and a boundary for livestock as it did a defensive structure. The Kilgarriff example, with its stone-facing on the earthen bank, sits in that middle ground between the purely earthen rath typical of lowland pasture country and the drystone cashels more characteristic of the rocky western coastline. Its south-west-facing slope setting would have offered both drainage and, on clear days, an open outlook across the landscape.