What makes the Gillardstown site particularly interesting is its bivallate form, meaning it was enclosed not by one but by two concentric earth and stone banks, each fronted by a fosse, the term used for the ditch dug to supply material for the bank above it. Between the two circuits runs a broad penannular space roughly eight metres wide, and within that space three radial banks divide the ring into distinct segments, an arrangement that is not especially common and whose purpose, whether related to livestock management, defence, or some ritual or social function, has not been resolved by scholarship.

Ringforts, known variously as raths or lios depending on regional tradition, were the dominant settlement form in early medieval Ireland, built and occupied broadly between the fifth and twelfth centuries. Most enclosed a single farmstead, with the bank and fosse serving as a boundary marking status and providing a modest deterrent to cattle raiders rather than any serious military defence. A bivallate example like this one, with its double circuit and carefully preserved entrance causeway on the south-east side, would likely have belonged to a household of some local standing. The entrance is still legible: a gap in the inner bank just under three metres wide leads across a causeway over the inner fosse, and a second gap and causeway carry the approach through the outer bank. Inside the enclosure, on the northern side of the interior, a low broad earthen bank appears to be the remnant of a sub-rectangular hut site, a rare survival of the domestic structures that once made these enclosures a place of daily life. Some of the earthworks have suffered over time; the inner bank is almost completely levelled along its north to north-north-east arc, and the outer bank to the south-west has been absorbed into a modern field boundary.