The River Vyrnwy, which begins at Lake Vyrnwy, flows eastwards through Powys gathering the waters of the Banwy, Cain and Tanat before forming part of the border between England and Wales, and joining the Severn near Melverley, Shropshire. The River Perry joins on the left bank above Shrewsbury whilst both the Rad Brook and the Rea Brook, which flows north from its source in the Stiperstones, join the Severn within the city. The left bank tributary, the River Tern, after flowing south from Market Drayton and being joined by the River Meese and the River Roden, meets the Severn at Attingham Park.