The most likely explanation is a souterrain, an underground stone-lined passage or chamber built during the early medieval period, typically for storage, refuge, or ventilation within a defended settlement. What makes this particular example quietly notable is precisely its ambiguity: the structure has not been excavated or confirmed, and what survives above ground is essentially the impression left by a probable collapse.

The site's paper trail is thin but telling. In 1937, a researcher named Broker recorded the presence of an underground chamber associated with the ringfort, which itself is a circular earthwork enclosure of the kind built across Ireland between roughly the fifth and twelfth centuries. Ringforts frequently incorporated souterrains, and the pairing here follows a well-established pattern. Whether the chamber Broker observed in 1937 was then still partly intact, or already reduced to the sunken ground that visitors might notice today, the record does not say. What remains is the ringfort, the reference, and those suggestive hollows in the south-east corner.