A souterrain is an underground stone-built passage or chamber, typically associated with early medieval ringforts and used for storage, refuge, or both. What makes this one quietly remarkable is that six ogham stones, each one carved with an early Irish script that predates the widespread use of the Latin alphabet in Ireland, were repurposed as roof lintels. Whoever built or modified this structure saw ancient inscribed monuments as useful building material, which tells you something about how the meaning of things shifts across generations.

The souterrain sits inside a rath, the earthen ringfort enclosure that surrounds it, and came to wider attention in the 1940s when the roof of a large passage collapsed, opening a way in. The Kerry Field Club recorded the discovery in 1945, describing a chamber roughly four feet wide and five feet high, roofed with stone slabs. What caught their attention was a fireplace with what they described as a well-constructed flue, and an air shaft positioned overhead, details that suggest a more considered design than simple underground storage would require. At least one further chamber was identified at the time but was not investigated. The landowner's own recollection added to the picture: an entrance leading into a small chamber, from which a second similar chamber could be reached, a modest but intriguing sequence of connected spaces underground.