Bencollaghduff is a 696-metre mountain in Connemara, County Galway, near the centre of the Twelve Bens in Connemara National Park. The range’s third-highest summit, it is linked to Benbaun by the Maumina col and to Bencorr by a high rocky ridge. Its name is usually taken to mean the peak of the black hags, with the “hags” understood as cormorants rather than supernatural beings; Irish forms include Binn Dhubh and the local dialect Binn Dubh. Ranked on several Irish mountain lists, it is also notable for its prominence. Walkers know it from the Glencoaghan and Owenglin Horseshoe routes, and it appears in Joseph O’Connor’s Star of the Sea.