Dún Aonghasa Dún Aenghus

On the edge of the cliffs fringing the southwest coast of Inishmore is the great stone fort of Dún Aenghus, a mighty semicircle of three roughly concentric enclosures on the brink of sheer cliffs dropping 300ft/90m to the sea. The inner court, 150ft/45m in diameter, is surrounded by a stepped drystone wall, 20ft/6m high and 18ft/5.4m thick at the base, containing various passages and chambers. The middle rampart is surrounded by a defense consisting of thousands of sharp-pointed stones set close together (chevaux-de-frise), in the manner of a modern tank barrier. From the edge of the cliff, one can catch a breathtaking glimpse of the surf far below and a splendid view over the sea.