Ceunant Llennyrch National Nature Reserve is one of several woodland reserves in the Vale of Ffestiniog in Gwynedd, Wales and runs from Llyn Trawsfynydd to the River Dwyryd, near the village of Maentwrog. The reserve's broad expanse of woodland coats a steep-sided gorge, through which the Afon Prysor cascades. At one point, the river is flanked by one hundred feet (30 m) high cliffs, which face each other only 10 metres (33 feet) apart. The high humidity offered by the falls creates the perfect environment for numerous damp-loving plants, due to the high humidity and high rainfall, it is technically a temperate rainforest. (en)