A souterrain is an underground stone-lined passage or chamber, typically associated with early medieval farmsteads, and used variously for storage, refuge, or ventilation. The entrance to this one has been recorded on maps for well over a century, labelled simply as "Caves" in the interior of a circular earthwork, yet no one has been able to reach it in living memory.

The earthwork surrounding it is a univallate rath, meaning a ringfort defined by a single bank and fosse, the fosse being the external ditch dug to create the raised enclosure. Ringforts of this type were the most common form of rural settlement in early medieval Ireland, and their presence in North Kerry is well documented. This particular example appears on both the 1842 and 1916 Ordnance Survey maps, which places it firmly in the cartographic record even as the physical site receded behind vegetation. C. Toal's North Kerry Archaeological Survey, published in 1995, describes a circular enclosed area with the souterrain marked within, but notes that by the time of survey the whole complex was completely overgrown and inaccessible. The maps tell you it is there; the land does not cooperate.