The 1914 edition of the Ordnance Survey six-inch map records it clearly enough: a small, irregularly shaped landmass roughly fifteen metres across, sitting in the lake. The cartographers of a century ago had no trouble finding it. Later investigators were not so fortunate.

A crannog is an artificial or partially artificial island, typically built during the early medieval period and used as a dwelling or place of refuge, constructed from layers of timber, peat, brushwood, and stone. This one was recorded on the map and catalogued accordingly, but when the site was physically visited, Lough Bannow had transformed into something considerably less navigable than a lake. The water had given way to a dense swamp choked with man-sized reeds and sally trees, the kind of vegetation that closes around a person and makes a fifteen-metre island perfectly easy to miss. Despite a thorough search, the crannog could not be located at all. It may lie submerged beneath the reed beds, absorbed into the swamped margins, or simply be indistinguishable from the surrounding ground. A second possible crannog lies approximately seventy-five metres to the north-north-west, suggesting the area may once have supported more than one such structure, though that one too remains unconfirmed.