Pen y Fan Pen y Fan Pen y Fan () is the highest peak in south Wales, situated in the Brecon Beacons National Park. At above sea-level, it is also the highest British peak south of Cadair Idris in Snowdonia. The twin summits of Pen y Fan and Corn Du at 873 m (2,864 ft) were formerly referred to as Cadair Arthur or 'Arthur's Seat'. The mountain and surrounding area are owned by the National Trust whose work parties attempt to combat the erosion caused by the passage of thousands of feet up and down this most popular of South Wales' peaks. The
Pen y Cymoedd Pen y Cymoedd Pen y Cymoedd ("Head of the Valleys") is a wind farm located between Neath and Aberdare in south Wales. It opened in 2017. Natural Resources Wales signed a lease agreement with Vattenfall of Sweden and its British-based subsidiary Vattenfall United Kingdom (formerly Nuon Renewables), to develop what will be the United Kingdom's highest altitude wind farm, on a site owned by Natural Resources Wales, previously the Forestry Commission Wales. The project has seen the installation of 76 turbines with a peak power of 228 MW, that are planned to operate for 25 years, and to generate up