What was once an underground passage, carefully constructed and deliberately hidden, has caved in and now exists only as a shallow, stone-filled groove in the earth, running east to west for less than ten metres. It is, in the most literal sense, a collapsed secret.

The feature is a souterrain, a type of man-made underground chamber or tunnel associated with early medieval settlement in Ireland, typically used for storage, refuge, or both. This particular example lies within the northern half of a rath, a circular enclosure of earthen banks that would once have defined a farmstead, most likely dating to the early medieval period. The combination is not unusual in itself; souterrains are frequently found in association with raths across the country. What makes Rooaunmore quietly notable is simply what has happened to it over time. The passage has fallen in on itself, and all that remains visible is a linear depression filled with stone, a faint trace of a structure that was built, used, and eventually forgotten. The site was recorded by McCaffrey in 1952, suggesting the collapsed state has been documented for at least seven decades.