Somewhere beneath the interior of a rath, the circular earthwork enclosure used as a farmstead and place of refuge throughout early medieval Ireland, lies what may once have been a souterrain: an underground passage or chamber, typically stone-lined, used for storage or concealment. No trace of it breaks the surface today.

The record of this feature depends almost entirely on a single observation made by Holt in 1912, who noticed a hollow within the rath and interpreted it as the sign of a collapsed souterrain. Souterrains were often built with corbelled stone roofs, and when the supporting structure fails, the ground above can sink or cave inward, leaving exactly the kind of depression Holt described. Whether his reading was correct is impossible to say now. Over a century later, nothing visible remains to confirm or complicate it, and the earthwork of the rath itself has presumably continued its slow return to ordinary-looking ground.