At Gortnagane in County Kerry, within a rath called Cathairín an Ghrafaigh, one or more souterrains were recorded in the mid-twentieth century, only for that record to note, almost in the same breath, that they had already been filled in. A souterrain is an underground stone-lined passage or chamber, typically associated with early medieval ringforts and raths, and thought to have served as a place of refuge or cold storage. Here, whatever passages once ran beneath the earthwork are gone, deliberately closed off, with no visible trace remaining at the surface.

The evidence for their existence comes from the Schools Manuscript collection, a body of folklore and local knowledge gathered in the 1940s by schoolchildren and their teachers across Ireland. That project captured details of local features, many of them already disappearing or altered, and it is through that record alone that the souterrains at Cathairín an Ghrafaigh are known at all. The rath itself, a roughly circular earthen enclosure of the kind built across Ireland during the early medieval period, survives as the physical context, but the underground elements that once gave it an additional layer of use or meaning have been lost entirely, their infilling presumably unremarkable enough at the time to leave no further documentation.