Corcomroe Abbey, also known as Sancta Maria de Petra Fertili (Saint Mary of the Fertile rock), was founded by Donal Mor O'Brien, King of Thomond, for Cistercian monks around 1195. The description is apt given its location in a sheltered, fertile green valley, which enabled the monks to be self-sufficient at such a remote site.

Among the numerous tombs and effigies in the chancel is one of a crowned figure, said to be  that of Conor O'Brien, grandson of the founder of the abbey, who was killed in battle nearby in 1268. 

The abbey was disestablished in 1554, as part of the English Reformation's dissolution of Catholic monasteries in England and Ireland.