Roughly 35 metres in diameter, the mound is encircled by a fosse, the term for a defensive ditch typically dug to reinforce an earthen enclosure, giving it the classic profile of a ringfort or similar early medieval construction. What makes it quietly remarkable is precisely this combination of obscurity and persistence: it was mapped, it was noted, and then it was swallowed whole by overgrowth.

The site appears on the third edition of the Ordnance Survey six-inch map, published in 1922, which places it clearly at the island's northern end. When archaeologist Paul Gosling compiled the Archaeological Inventory of County Galway, published in 1993, the earthwork was recorded but could not actually be examined, being inaccessible at the time of the visit due to dense vegetation. That a site could be documented while remaining entirely unreachable says something about the particular challenges of island archaeology in the west of Ireland, where lake crossings, seasonal flooding, and unchecked growth can conspire to keep even a reasonably substantial monument out of reach.