forts historical burren

There are three concentric walls, all abutting on to the edge of the cliff, as at Dun Aenghus on the Aran Islands. The innermost wall, which is also the thickest forms an almost complete circle, but the two outer walls (connected with each other by subsidiary walls, like a fan) only form a semicircle. The innermost wall contains three chambers within the wall, and excavation by the Harvard Archaeological Expedition to Ireland in 1934 showed that the roughly circular area it enclosed had a doze...