That discrepancy in height, modest on the interior but considerably more imposing when viewed from below, is one of the quiet effects of building on a slope: the natural gradient does some of the defensive work, making the enclosure appear more formidable from downhill than from within.

This is a rath, the most common type of early medieval settlement monument in Ireland, typically consisting of a circular area enclosed by one or more earthen banks and ditches, known as fosses. They served as farmsteads for free farming families, roughly between the fifth and twelfth centuries. The Kilbaylet example is modest in scale, with an interior diameter of twenty metres and a single earthen bank between two and 2.8 metres wide. Its external fosse, which would originally have run around the outside of the bank as a shallow ditch, is no longer visible on the western, downslope side, most likely due to natural erosion or gradual infilling over the centuries. A gap of about two metres at the south-west may represent the original entrance, though some of this has been lost to later disturbance. A field boundary now cuts across the northern perimeter, a reminder of how frequently these ancient enclosures have been absorbed, piece by piece, into later agricultural landscapes.

No internal features are visible at the surface, so there is no trace of the post-holes, hearths, or souterrains, the stone-lined underground passages sometimes associated with such sites, that archaeology occasionally reveals beneath similar earthworks elsewhere in the country. What remains is essentially the outline: a circle of raised ground on a hillside, its eastern bank still legible, its western edge fading into the slope.