It is, in fact, a substantial structure: an enclosure with an internal diameter of roughly 48 metres northeast to southwest and about 40 metres in the opposing direction, ringed by an external fosse and an outer bank. A fosse, in this context, is simply a defensive ditch dug around the perimeter, with the excavated material typically thrown outward to form the bank beyond it. The overall footprint, bank and all, extends to around 70 metres at its widest. That is a considerable statement to make on a hilltop, even if the land and the centuries have softened it considerably.

Enclosures of this type are scattered across Ireland, and their purposes varied: some served as ringforts, the farmsteads of early medieval landowners, while others may have had ceremonial or communal functions that archaeologists still debate. The Baunnaraha example sits quietly within that interpretive uncertainty. What the nineteenth-century Ordnance Survey mapping does confirm is that an entrance once pierced the outer bank in the southeast quadrant, a detail that hints at a deliberate, structured approach to the interior. More telling still, a field boundary running northwest to southeast along the northeastern side of the site has been built directly into the outer bank, cannibalising an ancient earthwork to serve the prosaic needs of later agriculture. It is a common enough story in the Irish landscape: one era's monument becomes the next era's convenient wall.