At Márthain on the Dingle Peninsula in County Kerry, a cairn, which is a mound of heaped stones typically raised over a burial or used as a landmark, was recorded at a specific location and then, at some point between its recording and any subsequent visit, ceased to be there at all. No mound, no scatter of stones, no obvious trace.

The cairn appeared in the 1986 Corca Dhuibhne archaeological survey of the Dingle Peninsula, compiled by J. Cuppage, a landmark survey of a peninsula that holds one of the densest concentrations of early field monuments in Ireland. Whether the structure was robbed for building material, ploughed out, or simply misidentified in the first place is not recorded. All that survives in the archaeological literature is the entry, and the note that nothing survives on the ground.