Tucked into Ireland’s wild northwest, Donegal/Dún na nGall, was for centuries the heartland of the O’Donnell clan, who ruled the Gaelic kingdom of Tír Chonaill. From the royal hillfort of Grianán of Aileach to the harbour at Rathmullan, where the Flight of the Earls sailed in 1607, the county wears its long history openly, and rewards anyone willing to wander.