Ogham is an early medieval script in which letters are represented by notches and strokes cut along the edge of a stone, most commonly used in Ireland between the fourth and seventh centuries to record names and lineages. The pair at Dunbell Big had been standing near the entrance to a souterrain, an underground stone-lined passage typically associated with a ringfort, leaning outward from the mound when they were found. The ringfort itself was being levelled at the time of discovery, and the workmen, finding the tall stones obstructive, smashed them without ceremony. The fragments, in a purplish-grey sandstone, were collected and painstakingly reassembled.

The episode was documented in the 1850s by J. G. Prim, who recorded the sorry condition of what became known as stone No. 2: forty-four pieces recovered, some minute, others reduced entirely to powder, with portions of the inscription obliterated beyond recovery. Reconstructed, the stone measured just over six feet three inches in length, tapering slightly and stepping down near the top. The inscription, as later read by Macalister in 1945 and by McManus in 1997, runs NAVALL[O] AVVI GENITTAC, a formula typical of ogham monuments, recording a personal name followed by a patronymic or lineage. Prim also published a map of the Dunbell raths in 1872 to 1873, marking the enclosure from which the stones came with the annotation 'D', the rath in which the oghams were found. Both stones are now held at the National Museum of Ireland, which is where the fragments have rested since their rescue from the field.