This one at Ballylegan in County Cork announces itself with nothing at all. The ringfort, a rath, which would originally have consisted of one or more circular earthen banks enclosing a domestic farmstead, probably of early medieval date, has been completely levelled. The surrounding field fences have been removed too, so that even the patchwork of boundaries that sometimes preserves a sense of an older landscape is gone. There is no visible surface trace of the site. What was once a circular enclosure roughly thirty metres across is now just a slope under tillage, facing northwest, indistinguishable from the field around it.

The site does survive, however, in two quite different ways. It appears on the Ordnance Survey six-inch map of 1842, rendered as a hachured circular enclosure, the convention used at the time to suggest an earthwork rising from the ground. By the 1934 revision of the same map series, only the northern side is shown, drawn as a solid line, suggesting the earthwork was already being degraded or consolidated by then. The more remarkable survival is aerial. Cropmarks, differential patterns in growing crops caused by buried features affecting soil moisture and nutrients below the surface, have revealed the ghost of the site in aerial photographs. Two fosses, the ditches that would have defined the outer boundary of the enclosure, show up as a circular cropmark. A second circular enclosure lies a short distance to the north-north-west, in the same field, making this a small cluster of related sites detectable only from the air.

There is little reason to visit the field itself, and no feature to look for on the ground. The interest here lies in what the site represents as a category of evidence: a place that has been thoroughly erased from the physical landscape but that archaeology, first through mapwork and then through aerial photography, has continued to locate and record. The past at Ballylegan is not buried so much as dissolved into the soil, readable only in the language of crop growth.