That small displacement is, in its quiet way, the most telling thing about it. Bullaun stones are boulders, typically of considerable age, in which one or more rounded depressions have been deliberately ground or worn into the surface. Their precise function is debated; they are associated with early Christian and pre-Christian ritual, with cursing and blessing traditions, and with the grinding of grain or pigments. This particular example, measuring about one metre by one and a quarter metres, was originally earthfast, meaning it was set firmly into the ground, with only part of its surface exposed. At some point before it was formally recorded, it had been shifted slightly from that original position.

The basin cut into its upper surface is roughly central, shallow rather than deep, measuring around 31 centimetres across and 8 centimetres at its deepest point. It is one of two bullaun stones recorded within a short distance of one another at Sroughan, which makes the site somewhat unusual; paired or clustered bullauins do occur elsewhere in Ireland, but a single example is more common. The boulder sits on what is now grazing land, looking out over a reservoir that is itself a product of significant intervention in this landscape. Poulaphuca Reservoir was created in the early 1940s when the River Liffey was dammed to generate hydroelectric power, flooding a considerable area of the Wicklow uplands. Whatever the original context of the bullaun stones was, that wider landscape was remade within living memory, making the continued presence of these ancient stones on the hillside above the waterline all the more striking.