Sgwd Henrhyd (Henrhyd Waterfall) in Powys, Wales, is the tallest waterfall in southern Wales with a drop of 90 feet (27 m). The falls occur where the small river, the Nant Llech drops over the faulted edge of a hard sandstone known as the Farewell Rock. It lies on National Trust land on the southern edge of the Brecon Beacons National Park.