This is a bullaun stone, a type of early medieval rock, often associated with ecclesiastical sites, that carries one or more cup-shaped depressions ground into its surface. The precise original purpose of these basins remains debated; they may have served liturgical or ritual functions, collected water considered to have curative or sacred properties, or acted as grinding stones. Whatever the explanation, their presence almost always signals proximity to an early Christian site.

This particular stone sits within the ecclesiastical enclosure of St Peakaun at Toureen, about four metres from the enclosure edge and roughly seventeen and a half metres to the north-east of a second, enclosed bullaun on the same site. The stone itself is modest in size, measuring 0.75 metres north to south and 0.49 metres east to west, but its central depression is substantial, around 0.31 metres in diameter and 0.23 metres deep. Noticeably, the eastern quadrant of the stone has broken away and is no longer present, leaving the depression incomplete on one side. That a site of this kind should contain two bullaun stones in relatively close proximity adds to its interest; the enclosed example nearby suggests the stones were valued enough, at some point, to receive deliberate protection or demarcation.