Doongrania, a place so eroded and modest that it can only be reached on foot at low tide, is traditionally associated with one of the most formidable figures in Irish maritime history: Gráinne Mhaol, or Granuaile, the sixteenth-century chieftain and seafarer known in English as Grace O'Malley. The name itself encodes the claim, "dún" being the Irish word for a fort or fortified place.

The tradition that Granuaile built a castle here was recorded independently by James Hardiman in 1846 and by the antiquarian T. J. Westropp in 1911, lending the association at least some antiquarian weight, even if the physical evidence has long since crumbled. When Westropp visited, he found only slight remains of a stone revetment, a retaining wall built against the slope of the ground, with no more than five or six courses of stonework still intact anywhere, possibly along the north-west side of the island. By the early 1990s, when the Archaeological Inventory of County Galway was compiled, only faint traces survived at all. The island also contains three clusters of house sites, suggesting that whatever its earlier function, Doongrania once supported a small settled community, now equally ghostly.

The island lies close to Inishbofin's harbour, which makes it easy to spot, but the crossing depends entirely on the tide. At low water, the link to the shore opens briefly; at high tide, Doongrania reverts to an island, taking whatever remains of its walls with it. Visitors prepared to time their approach carefully will find very little in the way of dramatic masonry, but the outline of those house sites, and the knowledge of what was reportedly here, give the place a quiet weight that its present condition alone would not suggest.