On a gentle rise in the grassland above the shore of Galway Bay, at Mulroog in County Galway, there is nothing to see. No stones, no earthwork, no depression in the turf. The site is, in the driest sense, a former ringfort, a type of roughly circular enclosure used in early medieval Ireland as a defended farmstead, typically defined here by a cashel, meaning a stone-built wall rather than an earthen bank.

The 1933 edition of the Ordnance Survey six-inch map recorded what was still visible at that point: the arc of a double-faced wall, curving from roughly north-east to south, with a field wall running north-north-west to south-south-east cutting across it at the south. A double-faced wall, as the name suggests, is constructed with two parallel lines of stonework filled between, and in 1952 the site was catalogued by McCaffrey as a circular stone fort with a wall some 3.6 metres wide and 0.54 metres high, already partly obscured by accumulated field rubble. By the time it was examined more recently, the landowner could recall only an arc of stones. That arc, too, is gone, levelled during field clearance. The land has been tidied, and in that tidying a structure that had stood for over a millennium was erased.

What remains is location and record. The rise still overlooks Galway Bay some 175 metres to the south-west, the view presumably much as it was when someone chose that spot to build. The archaeology is purely cartographic and documentary now, a site that exists in maps and classifications rather than in stone.