That is, in a sense, the point. Whatever once stood at this spot in Graigue, County Kilkenny, has vanished so completely that no trace remains at ground level, leaving only a name on a map and the faint outline of something that was once considered worth recording.

The name itself carries a small puzzle. The first element, cnoc, is the Irish word for hill, anglicised here as "knock"; the second, seanóg, is glossed in Patrick Dinneen's 1927 Irish dictionary as "the old Irish hood-cloak". Whether that meaning is literal, figurative, or simply a folk etymology attached to a forgotten feature is unclear. What the 1839 Ordnance Survey six-inch map does show, marked in Gothic script, is the name placed immediately west of a small roughly circular enclosure of about twenty metres in diameter, with a subrectangular enclosure of comparable size adjoining it to the northwest. By the time the map was revised in 1901, both enclosures had disappeared from the record entirely. The land around the site has been reclaimed and levelled, the River Glory, which once curved loosely to the south before bending northward and running east, has been straightened, and a small area of sand quarrying lies just south of where the monument is thought to have been. The landscape has been thoroughly rearranged, and whatever relationship the original feature had with the river, the rising ground, or the cloak-like name it carried has been erased along with it.