This route crosses Oxfordshire from west to east before climbing into the Chilterns. Beginning at Northleach in the Cotswolds, it follows the Windrush Valley on narrow lanes through pretty Burford to the bustling town of Witney. Here the route is unsignposted for a while, but you can follow the utilitarian cycle path beside the A40. In Oxford, the route passes colleges and chapels, heading out of town on the frenetic Cowley Road. Moderately busy roads lead to Thame where the lovely Phoenix Trail railway path makes for Princes Risborough. Here, a near-vertical climb (you'll have to push) marks the beginning of the narrow Chiltern lanes towards Chesham.