This nature reserve is part of an Afon Mawddach Site of Special Scientific Interest. During the 1800s peat was cut in the bog and taken by boat to Barmouth and Dolgellau to be used as fuel. A path passes through willow and alder scrub and, during the spring and summer months, reed bunting, whitethroat and sedge warbler may be heard or seen. Several kinds of butterfly may be spotted in the marshland. Siskin and redpoll are here in the autumn. The reserve can be reached by walking along the Mawddach Trail from either Arthog or Morfa Mawddach car park.
