The ground above it gives nothing away. There is no depression, no exposed stonework, no obvious sign that anything lies below. Yet local tradition insists the passage is there, sealed beneath the western half of the rath, waiting.

A rath is a circular earthen enclosure, typically built during the early medieval period as a farmstead or place of refuge, and souterrains were a common feature of such sites across Ireland. These underground stone-built passages and chambers served various purposes, most likely food storage, since the temperature underground stays cool and relatively constant, and possibly refuge in times of danger. The Rathrowan example, as it was recalled or described by those with local knowledge, followed a fairly recognisable pattern: an entrance opening in the western arc of the enclosure led into a stone-built passage, which in turn opened into a chamber. There may also have been a second passage branching off from that chamber, though this detail sits in the realm of the uncertain, preserved through oral tradition rather than excavation or direct survey.