That act of repurposing, using a formal commemorative marker as a structural lid, is what makes the discovery at Ballyknock so quietly arresting. The stone was not alone: it was one of fifteen ogham stones found together, all of them covering a souterrain, which is a type of dry-stone underground chamber or passage typically associated with early Irish settlement sites, often used for storage or refuge.

Ogham is an early medieval script, most commonly carved along the edges of standing stones, in which letters are represented by groups of notches and lines cut across a central stem. The Ballyknock stone is made of grit and measures three and a half feet tall, with a face just under two feet wide. Despite its worn surface, the inscription is described as being in fine scores and remains legible. Scholars have read it as ANM MEDDOGENI, a formula meaning roughly "name of Meddogen", with ANM being the Old Irish word for "name" and MEDDOGENI a personal name in the genitive case. R. A. S. Macalister included it in his 1945 corpus of ogham inscriptions, and Damian McManus returned to it in 2004, both arriving at the same reading. The concentration of fifteen such stones at a single souterrain is unusual; ogham stones were typically raised individually to mark persons of some standing, and their collective reuse as covering slabs suggests a later community either repurposing, or perhaps deliberately interring, a set of older monuments.

The stone itself is no longer in the field. It has been moved to the Stone Corridor at University College Cork, where it is on permanent display alongside other ogham stones from across Munster, allowing visitors to see the scored lettering at close range.