What emerged was a souterrain, an earth-cut underground structure of the kind built throughout early medieval Ireland, typically used for food storage, refuge, or both. This one had been sealed off from the surface for long enough that its collapse came as a surprise rather than a known hazard.

The structure consists of at least three chambers arranged in a rough north-to-south line. The central chamber is circular, roughly two metres in diameter, and retains a construction shaft at its north-west corner, the kind of opening left behind when builders finished their work and which sometimes served later as a ventilation point. Narrow creepholes, the low connecting passages characteristic of souterrain design, link this central space to further chambers at either end, both of which remain inaccessible. The northernmost chamber narrows as it runs towards the north-east, and this tapering passage may represent the structure's original entrance. The deliberate tightness of souterrain entrances was not accidental; a passage that forced anyone entering to crouch or crawl offered a natural defensive advantage.

The site sits in ordinary farmland, which is itself part of what makes it quietly notable. There is no monument to look at from the outside, no visible earthwork above the grass. The underground arrangement is there, documented and partially collapsed, beneath a working field on a Cork hillside.