It is not much to look at, but those low remnants are what remains of a structure that, as recently as the 1990s, was still substantial enough to appear on the landscape as a recognisable earthwork.

A rath is an early medieval enclosed farmstead, typically a roughly circular area defined by one or more earthen banks and ditches, within which a family would have lived and kept livestock. The Islandearagh example was recorded on the Ordnance Survey six-inch map of 1846 as a large subcircular enclosure with a diameter of around forty metres, already truncated to the south-east and south-west by an east-west field boundary that cut across it. That the enclosure was still visible nearly a century and a half after the first mapping is, in itself, a small measure of how enduring these earthworks could be. Local information indicates that it was levelled during land improvement works in the 1990s, a fate that befell a great many ringforts across Ireland during the latter decades of the twentieth century, when agricultural incentives encouraged the clearance of features that complicated the working of fields. The two remaining bank sections, set in level pasture, are now all that is legible of what the 1846 map recorded.