Whoever constructed it had access to at least three ogham stones and a cross-slab, and rather than leave them standing, they laid them into the walls. Ogham is an early Irish script in which letters are represented by a series of notches and strokes cut along the edge of a stone, typically recording a name in a genealogical formula. That these inscribed monuments ended up as building rubble tells its own quiet story about shifting priorities across the centuries.

One of the three ogham stones carries an inscription along the outside angle of its western face. The scholar R. A. S. Macalister, who catalogued hundreds of such stones across Ireland, read this one in 1945 as LADDIGNI MAQQI MUCCOI AN, a partial genealogical formula meaning roughly "of Laddigni, son of the tribe of An...". The stone is broken at that point, and whatever name followed the AN is gone. The rath, the roughly circular earthen enclosure within which the souterrain sits, and its associated stones were also noted by Judith Cuppage in her 1986 survey of the Dingle Peninsula. The reuse of ogham stones in later construction is not unusual in Kerry, but finding three of them, along with a cross-slab, within a single souterrain is a notable concentration of repurposed early medieval material.