Coed y Rhygen National Nature Reserve is located on the western shore of Llyn Trawsfynydd in Gwynedd, North Wales. As an example of Atlantic Rainforest, it is very wet and there are many different examples of mosses and liverworts that cover the ground and the trees. The reserve covers 2.78 hectares, is privately owned and is not open to the public.

52°54′50″N 3°57′54″W / 52.914°N 3.965°W / 52.914; -3.965