This one in Clooncah, in the undulating marshy pastureland of north County Galway, offers nothing of the sort at ground level. Walk across the field and you would have no idea you were standing inside a settlement that once measured roughly forty metres across. The ringfort, a circular enclosure of the kind that served as a farmstead and family enclosure throughout early medieval Ireland, has lost every visible surface trace. What remains is essentially a ghost, legible only from the air.

The first edition of the Ordnance Survey six-inch map, produced in the nineteenth century, recorded the site as a circular enclosure, which tells us that something was still distinguishable on the ground at that point. Since then, centuries of farming, drainage work, and the particular softness of marshy soil have conspired to erase the earthworks entirely. Aerial photographs, however, reveal the outline still pressed into the earth as a cropmark or soilmark, the kind of subtle variation in vegetation or soil colour that only becomes apparent when viewed from above. It is a reminder that the absence of visible archaeology does not mean the absence of archaeology itself.