The stones from Ballyknock in County Cork had been repurposed as roof slabs for a souterrain, the term for a stone-lined underground structure, typically associated with early Irish settlement sites and used for storage or refuge. Using ancient inscribed monuments as convenient building material tells you something about how attitudes to the past shift across centuries; what was once a marker of identity and lineage became, at some point, just a supply of good flat stone.

The stone in question is a stratified grit slab, just under four feet tall and roughly a foot wide, and its inscription is described as boldly pocked, cut on diametrically opposed angles along the edges, which is characteristic of ogham, the early Irish script that encodes letters as groups of notches and strokes running along a stemline. The text was read by R. A. S. Macalister in 1945 and again by Damian McManus in 2004, both arriving at the same reading: CLIUCOANAS MAQI MAQI-TRENI. The formula is a familiar one from ogham stones across Ireland and Scotland, essentially a declaration of descent, with MAQI meaning "son of". The stone announces someone named Cliucoanas, son of Maqi-Treni, a name otherwise known from other ogham inscriptions. That this personal record survived intact despite the stone being flipped onto a subterranean roof for an unknown period makes it rather remarkable.

The stone is now held on permanent display in the Stone Corridor at University College Cork, where it joins a substantial collection of ogham stones from across Munster. The Stone Corridor is one of the more quietly extraordinary places to encounter this script, with inscriptions from multiple sites gathered in a single walkable space.