It is not a spectacular monument in the way that some prehistoric sites announce themselves; it simply stands there, deliberate and unhurried, as it has for several thousand years. At roughly three metres tall and just over a metre wide, it is substantial enough to have been placed with intent, though by whom, and precisely why, remains unrecorded.

Standing stones of this kind are scattered throughout the Irish landscape, particularly in Munster, and west Cork has an unusually high concentration of them. They are generally understood to date from the Bronze Age, though some may be earlier or later, and their purposes remain a matter of debate among archaeologists. Boundary markers, ritual focal points, astronomical alignments, and memorials have all been proposed. The northeast-southwest orientation of the Greenane stone is a detail that some researchers find significant, as a number of Irish standing stones appear to have been positioned in relation to solar or lunar events on the horizon. Whether that applies here, or whether the alignment simply followed the natural lie of the land, is not known. What is clear is that whoever erected it chose a position with long, open views southward across one of the largest natural harbours on Ireland's Atlantic coast.