Cadair Berwyn is the highest summit in the Berwyn Range and the highest important summit in Wales outside the National Parks. It stands between the frontier between Denbighshire and Powys. Its height reaches 832 metres (2730 feet) and is classified as a Marilyn. The eastern slope is featured by rocky drops and crags, including Craig Berwyn and Craig y Llyn. Below the mountain is a small lake, called Llyn Lluncaws. There is a standing stone in the zone, situated close to the summit, between Cadair Berwyn and Tomle.