That small bureaucratic error turns out to be the least curious thing about it. When a nineteenth-century antiquary attempted to excavate what he called "the site of the old rath", he found the ground beneath him paved with enormous stone blocks, set on end and fitted tightly together, making digging almost impossibly difficult. A rath is a roughly circular earthen enclosure, typically of early medieval Irish origin, used as a farmstead or place of local assembly, but this one concealed something beneath its surface that went well beyond the ordinary.

The description comes from a Reverend Graves, writing in the Journal of the Royal Society of Antiquaries of Ireland in 1852 to 1853, in an article focused on the broader Ballon Hill cemetery nearby. His brief note on the rath is vivid and practical, the record of someone who tried to dig and found the earth fighting back. The enclosure, roughly sixty metres in diameter, was later identified through aerial imagery by the Ballon Hill Archaeology Project, whose researcher Nial O'Neill located it on mapping software at a position approximately one hundred metres north-northeast of where it had been plotted on the 1995 Record of Monuments and Places map. When the earlier mapping was reviewed, it became clear there had never been solid evidence for that original location in the first place, and the monument's recorded position was corrected accordingly.

What lies beneath the surface of that closely fitted stone pavement remains unexcavated and unexplained. Whether the stones formed a deliberate floor, a foundation, or something stranger is not recorded.