The Oxford–Cambridge Arc (formerly the Cambridge – Milton Keynes – Oxford corridor) is a notional arc of agricultural and urban land at about 80 kilometres (50 miles) radius of London, in south central England. It runs between the two English university cities of Oxford and Cambridge via Milton Keynes and in Bedfordshire, Buckinghamshire, Cambridgeshire, Northamptonshire, Oxfordshire at the northern rim of the London commuter belt. It is significant only in economic geography, with little physical geography in common.