What sets it apart from the more modest single-bank examples scattered across the Irish countryside is the presence of a second, taller enclosing bank, separated from the inner one by a fosse, or ditch. That outer bank still stands at around 1.75 metres, while the inner bank reaches 1.45 metres on its interior face, figures that convey something of the effort and intention behind the original construction.

Ringforts, known in Irish as raths when built primarily of earth, were the typical farmstead enclosures of early medieval Ireland, broadly spanning the period from the fifth to the twelfth century. They range from modest single-banked enclosures to more elaborate multivallate examples like this one, where the additional bank and fosse may signal a higher-status household or a site that required greater security. The Ballygarvan example is nearly circular, measuring 38.6 metres east to west and 38.1 metres north to south, with a saucer-shaped interior. Its original entrance to the south-west is just under two metres wide and retains a causeway crossing the fosse, though a corresponding gap through the outer bank, nearly four metres across, has since been blocked with a stone wall. The inner bank shows some disturbance along its north-east arc. Beneath the northern half of the interior lies a souterrain, an underground stone-lined passage or chamber that was typically used for storage or, in times of danger, refuge, and which speaks to the domestic life once carried on within these banks.