These slabs are the visible trace of a souterrain, an underground passage or chamber built during the early medieval period, typically used for storage, refuge, or both. What makes this one quietly unusual is its position: not inside the ringfort's enclosure, but outside its outer bank, sitting beyond the perimeter rather than within the protection it would have afforded.

Ringforts, the circular enclosures defined by earthen banks or stone walls that dot the Irish countryside in their thousands, were the farmsteads and homesteads of early medieval Ireland, occupied roughly between the fifth and twelfth centuries. Souterrains are frequently found within them, dug into the interior and roofed with stone lintels. Finding one outside the bank is less typical and raises quiet questions about function, sequence, or the relationship between the underground structure and the enclosure beside it. There is also, according to the available record, a possible second souterrain within the ringfort itself at Caherbaroul, which would make this a site with underground features on both sides of its defining boundary.