That name, Doonigar, appears on the 1901 Ordnance Survey six-inch map, and it is almost all the evidence of human connection that survives. The site is a promontory fort, or at least a possible one, which is a category of prehistoric or early medieval enclosure using a headland's natural sea cliffs as its main defence, with an earthwork or wall closing off the landward side. At Doonigar, even that closing element is uncertain.

The antiquarian Thomas Johnson Westropp visited and wrote about the site in 1921, describing it as a platform of rock with a very irregular plan, inaccessible from the land side and reachable only by boat. He found, by his own account, apparently no trace of fencing or of human occupation save the name. What he did find was a chasm some 70 to 80 feet deep dropping beneath the platform, which he suggested may have been defence enough on its own, with any slight structural works along the edge likely obliterated by rock falls over the centuries. A later survey by O'Sullivan in 1992 recorded the remains of a wall on the western and north-western sides, along with two sea arches running beneath the rock. So there is something there, or was, though whether it represents deliberate fortification or the slow erosion of a landscape that was never much altered by human hands remains genuinely open.

Access is the central difficulty. Westropp's observation that the platform can be reached from a boat still holds; there is no land approach. Bear Island itself requires a ferry from Castletownbere, and Doonigar sits on the island's more exposed western shore. Anyone drawn to the site should be aware that the sea arches and the chasm Westropp described make the rock formation as physically precarious as it is archaeologically ambiguous.