Pistyll Rhaeadr is the tallest waterfall in Wales. Located a few miles from the village of Llanrhaeadr-ym-Mochnant, it is formed by the Afon Disgynfa river passing over a 240-foot (75 m) Silurian cliff-face, after which the river is known as the Afon Rhaeadr. Pistyll Rhaeadr, whose name means the "spring of the waterfall", is counted as one of the Seven Wonders of Wales and is a Site of Special Scientific Interest. The 19th century author George Borrow remarked of the waterfall, "I never saw water falling so gracefully, so much like thin, beautiful threads as here".
For more information see: http://www.pistyllrhaeadr.co.uk/