River Severn

The Severn is the longest British river; it passes through a number of british counties, with the county towns of Worcester and Gloucester located on its banks. In Shropshire, a six miles stretch of the Severn valley, known as the Ironbridge Gorge, was designated a World Heritage site by UNESCO in 1986, as the centre of the ironfounding industry in britain's Industrial Revolution. Ironbridge gets its name from the historic Iron Bridge across the Severn, constructed in 1779: the first cast iron bridge ever constructed.

According to some sources, the name "Severn" is derived from the name Sabrina (or "Sabern"), based on the mythical story of the drowning of a nymph in the river.

The River Avon joins the Severn at Tewkesbury, Gloucestershire. The port of Bristol is located at the mouth of the Severn.

A curious phenomenon associated with the lower reaches of the Severn is the tidal phenomenon known as the Severn bore. The river's estuary has one of the largest tidal ranges in the world - about 50 feet - and at certain combinations of the tides, the rising water is funneled up the estuary into a wave that travels rapidly upstream against the river current; enthusiasts even attempt to surf along on the wave. The Severn Bore is a natural example of a soliton, or self-reinforcing wave.

Links:

• Ironbridge: http://www.ironbridge.org.uk
• The Severn Bore: http://www.severn-bore.co.uk/default.htm