It measures only about ten metres across, carries a single tree, and has, as far as records show, never been formally visited by a researcher. That last detail is quietly remarkable. The island is almost certainly a crannog, an artificial or partly artificial island dwelling built up from timber, stone, and earth, typically during the early medieval period, though some were constructed and reused across many centuries.

The island does not appear as a distinct feature on all historical mapping. It shows up clearly as a small island only from the 1908 edition of the six-inch Ordnance Survey map, and it is consistently visible in aerial photography. Its presence was first brought to wider attention by Anne-Karoline Distel. The bay in which it sits is modest in scale, roughly two hundred metres east to west and between eighty and a hundred metres north to south, which means the island would have been readily accessible by boat from the shore while still offering the kind of separation that made crannogs attractive as defensible homesteads or places of refuge throughout early Irish history.