We initially walk along the route of the old Buckingham canal (branch of the Grand Union Canal) from Thornton towards Buckingham, including a short break at a restored lock. After passing a nature reserve and crossing the river we return via the medieval Thornborough bridge, where we stop for a lunch break. We then pass ancient tumuli and walk through Thornborough village before returning to our starting point. The canal path is overgrown in places, so be prepared for some nettles and brambles. Bring a packed lunch.
Meet at the Thornton turning off the A422. Turn left travelling from MK and immediately on the right is a lay-by section of the old road with plenty of parking space: