That the boulder is there, and that it matters, is taken largely on faith, local memory, and older fieldwork. It is a bullaun stone, a type of ancient carved rock featuring one or more deliberately hollowed basins ground into its surface. The purpose of such stones is not definitively settled; they appear across Ireland in association with early ecclesiastical sites and sacred landscapes, and the water that collects in their basins was often regarded as having curative or protective properties.

This particular boulder carries four basins, each roughly 27 to 30 centimetres across and about 10 to 12 centimetres deep. Three of them are arranged in a line along the eastern side of the stone, with the fourth positioned on the opposite, western side. A possible fifth basin may exist on the eastern face, but it lies entirely beneath accumulated peat and has never been properly examined. The stone is earthfast, meaning it is set into the ground rather than loose, which is typical of bullauns that have remained in or near their original position. Locally, the basins are known as the hand print of St Lawrence O'Toole, the twelfth-century Archbishop of Dublin who was born in County Kildare and had strong associations with Glendalough, not far to the west. The attribution draws the stone into a wider landscape of early Christian memory, where physical marks in rock became anchored to the lives of saints over generations of storytelling.