The source of the River Severn is high on Plynlimon, in the uplands of mid Wales, from where both river and walk descend to Llanidloes, Newtown, Powys and Welshpool. It then follows the towpath of the Montgomeryshire Canal, passing through Shrewsbury, Shropshire and the Severn Gorge. It passes the cradle of the Industrial Revolution at Ironbridge before passing through Bridgnorth, Hampton Loade and Highley (in Shropshire), and Bewdley in Worcestershire, Stourport-on-Severn, Worcester, Upton-upon-Severn and Tewkesbury. It enters Gloucestershire and passes through Gloucester itself before passing Berkeley Castle and following the Severn Estuary past Slimbridge. Originally, the path finished at Severn Beach, but it has recently been extended to Bristol via Lawrence Weston, Shirehampton and through the Avon Gorge.