Ciro Santilli The city clearly exists because it is in the confluence of the river Thames and the River Cherwell. In such confluences, terrain tends to be flat, and fords are also common, with crossings wide and shallow, and so it was an important crossing place.
Notably, the Cherwell is a natural link between London and the North towards Coventry, and then Birmingham, as it, and then the Thames in which it goes into, puncture through both the Chilterns, then North Essex Downs and the Cotswolds hills. The M40.