Not destroyed, not moved to a museum, not even definitively lost, just absent from the spot where it was recorded, leaving behind only a nineteenth-century description and an unanswered question.

In 1884, the geologist G. H. Kinahan documented what he called stone B at Mongnacool in County Wicklow: a large, roundish mass of granite whose more conspicuous face sloped nearly due south, and on which five cup marks were visible, though already more or less obliterated by weathering. Cup marks are among the oldest and most enigmatic forms of prehistoric art found across Ireland and Britain, shallow circular depressions pecked into rock surfaces, whose purpose remains genuinely unknown. Kinahan noted their deteriorated condition even then, which suggests the stone had already been exposed to the elements for a very long time. When the site was revisited in 1990 using the location indicated in Kinahan's own text, the stone could not be found. Whether it lies buried, overgrown, or simply misidentified in its original coordinates is unclear.