The Aran Islands are 3 rocky isles guarding the mouth of Galway Bay, in western Ireland. They’re known for their ancient sites. The largest island, Inishmore, is home to the prehistoric fort of Dún Aonghasa, perched on top of a high cliff. Nearby is the Worm Hole, a rectangular natural pool. The medieval ruins of the Seven Churches are in the northwest. View of Cliff of Moher from Atlantic ocean.