«Britain's longest river begins its journey at a boggy spot just over 1,968ft above sea level on Plynlimon in the Cambrian mountains. The source is marked by two huge wooden posts, one inscribed in Welsh and one in English. [...] The Severn's
tributaries include the Teme, Stour,
Wye,
Vyrnwy, Tern and Avon. [...] There are 100 bridges across the Severn, including the eponymous Severn Bridge. There are other road bridges, railway bridges, footbridges, farm bridges, toll bridges [...] One of the world's biggest bores [...] There are about 260 bores on the Severn each year, usually two a day on about 130 days a year, around the vernal and autumnal equinoxes (February to April and August to October). There are especially large bores on about 25 days a year [...] the Severn Bore is one of the highest in the world. [...] The bore travels 21 miles [...]»
