There are numerous prehistoric structures in the Burren and the Gleninsheen Wedge Tomb, in Carran County Clare, is just one impressive example. It dates from around 2500BC.
Wedge tombs are named for their wedge shaped plan: they are narrower and lower towards the rear. The limestone area of The Burren provides plenty of large slabs for such purposes. In the same area there are over seventy megalithic tombs.