Corcomroe Abbey is the ruin of a Cistercian monastery founded around 1200 in a green valley a few kilometres east of Ballyvaughan. Its old name, St Mary of the Fertile Rock, is a nice joke about its surroundings. The roof is gone but the church is otherwise in good shape, and its stone carvings are counted among the finest in any Cistercian church in Ireland.
Near the altar is the tomb of the O'Loughlins, the "Princes of Burren" who ruled the area until the 17th century. W. B. Yeats set his play The Dreaming of Bones here. It's a National Monument and open to the public.