The boulder marks the entrance to a souterrain, an artificial tunnel or chamber built into the earth, typically used in early medieval Ireland for storage, refuge, or both. This one is now inaccessible, its mouth blocked, its interior unrecorded in any recent survey. It is the kind of detail that rewards a second look at what might otherwise appear to be a modest, unremarkable earthwork.

The rath itself is a univallate ringfort, meaning it is defended by a single enclosing bank rather than the multiple concentric rings found at higher-status sites. Its sub-circular interior measures roughly 23 metres north to south and 27 metres east to west, a scale typical of a small farmstead enclosure from the early medieval period, roughly the fifth to twelfth centuries, when ringforts were the dominant settlement form across rural Ireland. The enclosing bank is low and wide, standing only half a metre in height both externally and internally, with a base width of around four metres. That modest profile is partly explained by what has happened to the site since it was built: a track running northwest to southeast now cuts straight through the enclosure, dividing it roughly in half. The souterrain, covered by its boulder in the west-northwest sector of the interior, was constructed of stone, though its full extent and layout remain unknown.