This Cistercian abbey, founded in 1198, was never especially grand but the ruined walls and arches are still picturesque, especially when the daffodils are in bloom. There are walks in the vicinity and nice picnic spots near the river. It's 2 miles northwest of Dolgellau, signposted from the A470.
Cymer Abbey
Snowdonia National Park (Parc Cenedlaethol Eryri)