The bank holds a diameter of 34.5 metres, rises to an internal height of 1.6 metres, and is accompanied by a shallow external fosse, the ditch that once made the whole enclosure a more formidable proposition. The entrance faces south, as is common with these structures, and the interior remains clear of overgrowth, which means the full shape of the place reads easily at ground level.

This is a rath, the earthen variety of ringfort, a class of monument built predominantly in early medieval Ireland, roughly between the fifth and twelfth centuries, as an enclosed farmstead for a family of some local standing. Thousands survive across the island, yet each one carries its own character. What makes the Kilblaffer example particularly interesting is a possible souterrain recorded in its northern half. A souterrain is an underground stone-lined passage or chamber, typically associated with ringforts, and thought to have served for storage, refuge, or both. The word itself comes from the French for underground passage, though the structures are thoroughly Irish in their distribution and use. Whether the passage here is fully intact, partially collapsed, or simply inferred from surface subsidence is not recorded, but its presence, even as a possibility, hints at a more complex interior life beneath what looks, from outside the bank, like a straightforward enclosure.