The souterrain, an underground stone-lined passage or chamber typically built during the early medieval period as a place of refuge or cold storage, left no mark on the surface above it. No hollow in the ground, no depression in the grass, nothing to betray its presence until the earth simply gave way.

The story passed into local knowledge rather than formal record. According to information relayed by Dr. David J. Burdon, the collapse occurred during agricultural work with horse-drawn machinery, which is how the passage came to be known at all. It sits within the western half of a ringfort, the circular earthwork enclosures that are among the most common archaeological monuments in Ireland, typically dating to between the sixth and tenth centuries. Souterrains were frequently built in association with ringforts, often accessible from inside the enclosed area. What makes this one particularly curious is that it is thought to extend beyond the boundary of the ringfort itself, pushing out under ground that shows no sign of anything unusual overhead.

There is nothing to see at ground level. The souterrain remains unexcavated and its full extent unmapped, which means the collapse point and whatever lies beyond it are still largely unknown. It is the kind of site that exists more as a fact about a place than as a place in itself, a reminder that early medieval Ireland built as much underground as above it.