The River Churn is the first tributary river of the River Thames. It also rises in the Cotswolds, however at Seven Springs near Cheltenham, Gloucestershire, England and flows south across the Cotswold dip slope, passing through Cirencester and joining the Thames facing a rural part of the parish of Cricklade in Wiltshire. Its length from source to confluence with the Thames is considerably greater than the Thames from Thames Head (its source) to the same confluence but, more variable in flow, the Churn is regarded as a tributary historically and therefore by most geography guides.