The source of the river is in northern Northamptonshire near the village of Welford. For the first few miles of its length it forms the border between Northamptonshire and Leicestershire, it runs east to west, just north of the Cotswolds, through Rugby, Leamington Spa, Stratford-upon-Avon and Pershore and through the Vale of Evesham. It joins the River Severn at Tewkesbury. It is 154km (96m) long. The Stratford-upon-Avon Canal is connected to it by a lock in Stratford. Its tributaries include the Rivers Leam, Stour, Sowe, Dene, Arrow, Swift and Isonbourn as well as many streams and brooks. It has many weirs, lockss and sluice gates on it. The river is also very deep in some places.