Llyn Clywedog snakes through the hills north of Llanidloes behind a concrete buttress dam that, at 72m, is the tallest concrete dam in the UK. It was built between 1963 and 1967 to regulate the flow of the young River Severn. A road runs along the eastern shore with parking and viewpoints, and there’s open access to the moorland above. Caersws station is about 13km east.
