Shown on the 1907 edition of the Ordnance Survey six-inch map as a small circle roughly fifteen metres across, it surfaces today only at very low water levels, revealing a grass-covered mound of earth and stone measuring some thirty-three metres north to south and fourteen metres east to west, ringed by reeds. What makes it quietly puzzling is that, despite sitting in the same lough as a confirmed crannog roughly forty metres to the south-east, this particular island shows no evidence of artificial construction. A crannog, for context, is a man-made or man-modified island, typically built during the early medieval period as a defended dwelling place, and Ireland's lakes contain hundreds of them. This island, however, appears to be entirely natural, a coincidence of geology and water level that has given it the look of something deliberate without any of the archaeology to back that up.

The lough itself occupies a sub-oval basin in its northern section, stretching roughly 1.4 kilometres east to west and 900 metres north to south, with Turf Island sitting near its centre. The unconfirmed island lies approximately sixty metres south-west of Turf Island's southern tip. Its near-neighbour, the catalogued crannog to the south-east, is a separate and distinct site, and the proximity of the two raises the kind of question that is easier to pose than to answer: whether the natural island's resemblance to a crannog ever led people to use or modify it, or whether it has simply sat beneath the surface of the lough, mostly invisible, for centuries without attracting any attention at all.