Whitland was founded by the Normans in 1140 under the direction of St Bernard’s abbey at Clairvaux, but when the Welsh reconquered the area it became a Welsh house and the mother of all the Welsh Cistercian foundations. The abbey suffered savage reprisals for its support of Llywelyn ap Gruffydd and Owain Glyndwr, and there were frequent accusations of financial malpractice to contend with as well. As a result, the remains of the buildings are typical of the first austerity of Cistercian building: there was never any money to rebuild in a fancy Gothic style. Recent excavation and consolidation has made the site easier to understand, and there is a good interpretative board.
More on the Monastic Wales web site.