Cup marks are among the oldest forms of human mark-making found in Ireland, shallow circular depressions ground or pecked into rock surfaces, whose precise purpose remains genuinely unknown. Whether they served a ritual function, marked territorial boundaries, or meant something else entirely, archaeologists have debated for generations. The stone at Knockatassonig belongs to a category that is stranger still: the monument that local knowledge insists exists, but that no subsequent field inspection has been able to find.

The site entered the archaeological record on the basis of local information, a common enough route for rural Irish monuments, where farmers and landowners often preserve knowledge of features that might otherwise go unrecorded. But when fieldworkers went to confirm the cupmarked stone's presence in the area described, they came away empty-handed. The rough, hilly terrain of this part of Cork is not especially forgiving ground for surveys; stones can be obscured by vegetation, buried under peat, or simply sit at an angle that makes their markings invisible without the right light. The stone has neither been confirmed nor formally ruled out.