At Ballybrack in County Dublin, a large capstone measuring roughly three metres by two once lay on top of a low cultivated hill, covering what local people called Leaba na Saigh, Irish for "the greyhound's bed." Nobody in the area seemed to know it by that name except one elderly man, and within a generation of it being recorded, the structure had vanished entirely.

When the antiquarian and Celtic scholar Eugene O'Curry visited in 1837 as part of the Ordnance Survey's effort to document historic sites across Ireland, he spoke with a ninety-year-old local man named Peter Welsh, who recalled hearing the old Irish-speaking people of his childhood use that name for the site. O'Curry noted that the monument had already been partly opened, though when or by whom nobody could say. The first edition of the six-inch Ordnance Survey map, published in 1843, recorded it as a small circular cairn, the term for a mound of stones often associated with prehistoric burial. By the time the map was revised in 1863, the entry had changed to "Giant's Grave (site of)," indicating that even the physical remains were gone. The confusion surrounding the site did not end there. William Wakeman, writing in 1891, conflated it with a different feature described by O'Neill in 1852, situated about 1.3 kilometres to the north-east. That error was then repeated by W. C. Borlase in 1897 and followed by several subsequent commentators well into the twentieth century. O'Neill's site, it turns out, is a natural rock formation rather than a man-made monument at all.

Nothing of the Ballybrack structure survives above ground today, and the archaeological record is too thin to confirm definitively that it was a megalithic tomb, the kind of prehistoric chamber burial familiar from better-preserved examples elsewhere in Ireland. What remains is a tangle of mistaken identifications, a ninety-year-old man's childhood memory, and a single evocative name that outlasted the stone it described.