Known locally as Oileán an Fort, or Colt Island in English, the place holds a tradition that a fortification once stood here, positioned to watch over the narrow channel between the island and the mainland. Today there is nothing to see. No earthwork, no stonework, no depression in the ground. Whatever was here has gone entirely.

The structure, whatever its nature, was destroyed during the construction of a bridge and causeway in the nineteenth century, the kind of improvement project that connected remote communities to the mainland but often swept away earlier features without record. Local tradition remembered it as a fort guarding the crossing-point, which would have made strategic sense given the narrowness of the channel and the value of controlling movement between Inis Ní and the shore. The cartographer and writer Tim Robinson, who documented Connemara with exceptional care, suggested a more modest possibility: that it may have been nothing grander than a bailiff's hut, a small building used by an estate agent or rent collector managing land on the island. The gap between those two interpretations, a defensive fortification on one hand and a functional agricultural building on the other, has never been resolved, and now likely never will be.