It is not a towering monolith. At just over a metre high and roughly the same width at its base, it is the kind of prehistoric marker that a person could easily mistake for a naturally occurring outcrop, of which there are several nearby on the lower slopes of Camarahill. What distinguishes it is its deliberate placement and orientation, aligned north to south, with a flat eastern face and a more rounded western one, tapering as it rises.

The stone sits above the Little Slaney River, which runs close by to the east, on land that is geologically characteristic of this part of Wicklow, where granite pushes through the surface in irregular formations. Its position is not incidental to its surroundings. From where it stands, the hillfort known as Brusselstown Ring is visible to the west, Keadeen Mountain to the southwest, and both the Sugarloaf and Lobawn to the north. Whether or not these alignments were intentional, the stone occupies a point from which several significant landmarks of the wider landscape are simultaneously legible. A second standing stone lies approximately 130 metres to the north, suggesting this was never quite a solitary monument, even if the relationship between the two is now unclear.

Standing stones of this kind are among the least understood of Ireland's prehistoric remains. They appear across the country in a variety of sizes and settings, sometimes in pairs or loose groupings, sometimes alone, and their original purposes, territorial markers, ritual sites, burial indicators, or something else entirely, remain genuinely uncertain. The Coan stone, modest in scale and quietly situated above an unremarkable stretch of river valley, fits no tidy category, which is perhaps what makes it worth noticing.