Once reachable by a narrow neck of loose, jointed rock that connected it to the Inishbofin mainland, that causeway has long since collapsed into the sea, leaving behind a cliff-bound platform of roughly one hectare with no easy way on or off. The place is recorded in the Ordnance Survey Name Books of 1839 as Dún na hIníne, and it carries an older alias too: Finnguine's Fort, a name that hints at some remembered ownership or legend that history has otherwise let slip.

The antiquarian Thomas Johnson Westropp surveyed Inishbofin in the early twentieth century, but even he could not reach this particular islet and had to observe it from the mainland. Writing in 1911, he described what he could make out: a long reach of revetment wall, that is, a retaining wall built to hold back an earthen slope, running along the western side near the top of a grassy incline. He also noted what appeared to be a partial hut-site sitting on the crumbling cliff edge opposite the old neck of rock, and, towards the centre of the flat platform, a low mound so regular in form that he considered it unlikely to be natural. A dunadh, in Irish tradition, is a fortified enclosure or stronghold, and the combination of a defensive wall, internal structures, and a central mound fits loosely within that pattern, though without excavation any interpretation remains speculative.

Of everything Westropp described, only the revetment wall remains visible from the mainland today. The hut-site and the mound, positioned as they were on crumbling ground, may have gone the way of the causeway itself. The island has not been formally visited or surveyed since Westropp's time, and the sea continues its work on the rock beneath it.