The 1842 Ordnance Survey six-inch map recorded a circle of four stones at this spot, one of them already fallen, and labelled the group 'Gallauns', the old Irish term for standing stones. By the time the surveyors returned for the 1906 edition, only one stone appeared on the map, and the 1934 revision told the same reduced story. Whether the others were removed, buried, or simply missed is not recorded. The survivor stands 1.35 metres high, subrectangular in cross-section, and is orientated with its long axis running northeast to southwest, a alignment shared by many prehistoric standing stones across Munster. Small packing stones, the wedged material used to stabilise the upright when it was first erected, are still visible at the base, which gives the site a quietly legible quality; you can see, in a small way, the mechanics of how it was put up.

The name 'Gallauns' on that mid-nineteenth century map is itself worth pausing over. It suggests that local people in the 1840s still had a working word for what they were looking at, a collective memory of the stones as a meaningful category of thing, even if the circle was already incomplete by then. The loss of three of the four stones between 1842 and 1906 is a pattern repeated across Cork and the wider country, where agricultural clearance, road building, and the simple demands of a working landscape quietly dismantled prehistoric arrangements that had stood for millennia. The lone gallaun at Dunmahon is as much a record of that attrition as it is of whatever purpose the original circle served.