In the gently undulating pasture of Carrowbrickeen in County Sligo, there is a place that has never appeared on any edition of the Ordnance Survey six-inch map, leaves no trace whatsoever at ground level, and is known to exist at all only because an aerial photograph caught a faint circular shadow in the earth. That shadow suggests an enclosure of roughly twenty metres in diameter, the kind of modest circular earthwork that appears throughout the Irish countryside, typically as a ringfort or ráth, a form of enclosed farmstead used from the early medieval period onwards. Whether this particular feature is of that tradition, or something older, or something else entirely, cannot be said with confidence. The ground keeps its silence.