At Ballybrone in County Galway, a grouping of stones was recorded, mapped, and assigned to no known monument type, only to disappear entirely from the visible landscape. Whatever arrangement once existed here, it did not fit neatly enough to be called a cairn, a cist, or a standing stone alignment, and yet it was considered significant enough to mark.

The stones appear on both the first edition and the 1933 third edition of the Ordnance Survey six-inch maps, suggesting they were a legible feature of the landscape across at least several decades of the nineteenth and twentieth centuries. They sat roughly ten metres west-northwest of a ringfort, the circular earthwork enclosure that was the standard form of early medieval farmstead across Ireland, and that proximity may or may not have been coincidental. By the time de Valera and Ó Nualláin included the site in their 1972 survey of megalithic monuments, no visible surface trace remained. The stones had gone, been removed, been buried, or perhaps had never been quite what earlier mapmakers assumed them to be.