A Cistercian abbey founded c. 1200 by William, the Earl Marshall, and named after Tintern in Wales. The remains consist of nave, chancel, tower, chapel, and cloister. It was partly converted into living quarters after 1541, and further adapted over the centuries. The Abbey was occupied by the Colclough family from the 16th century until the 1960s. As this site is managed by the OPW, school tour visits are permitted free of charge provided certain conditions are met.