​Geography Department 
De Aston School Academy Trust

Britain's longest river begins its journey at a boggy spot just over 1,968ft above sea level on Plynlimon in the Cambrian mountains. From there, it descends into the agricultural valleys of eastern Wales and crosses the Shropshire plain, becoming tidal to the north of Gloucester. Two hundred and twenty miles from its source, the river fans out to form the Severn Estuary before flowing through the Bristol Channel. The Severn's tributaries include the Teme, Stour, Wye, Vyrnwy, Tern and Avon.