Severn

The River Severn (Welsh: Afon Hafren, pronounced [ˈavɔn ˈhavrɛn]) is the longest river in Great Britain, with a length of 220 miles (354 km). It is also the river with the most voluminous flow of water by far in all of England and Wales, with an average flow rate of 107 m3/s (3,800 cu ft/s) at Apperley, Gloucestershire. It rises in the Cambrian Mountains in mid Wales, at an altitude of 610 m (2,000 ft), on the Plynlimon massif, which lies close to the Ceredigion/Powys border near Llanidloes. Th...