At first glance it looks every bit the prehistoric standing stone, the kind of deliberate upright that punctuates the Irish landscape and draws the eye of anyone with an interest in antiquity. But there is a complication: it does not appear on any edition of the Ordnance Survey six-inch maps, the standard reference for features of this kind, and the suspicion among those who have examined it is that it may never have been placed there by human hands at all.

The boulder is approximately circular in cross-section, roughly 1.5 metres wide and 1.85 metres tall, and its presence on the ridge is most likely explained not by Neolithic intention but by glacial accident. It may well be an erratic, a stone carried far from its origin by a glacier during the last ice age and deposited wherever the ice happened to melt. Erratics can end up in improbable positions, sometimes balanced, sometimes upright, occasionally tapering in ways that read as deliberate from a distance. The distinction matters, because genuine standing stones are monuments, set in place by people for purposes, ritual, territorial, or commemorative, that archaeology still works to understand. An erratic is geology rather than archaeology, shaped by nothing more purposeful than the slow movement of ice.