Thornborough Bridge

Thornborough Bridge is located on the original Bletchley and Buckingham road, now bypassed by a modern bridge in 1974 for the A421. The bridge is accessible to walkers from an adjacent lay-by.
The bridge straddles the parish boundaries of Thornborough and Buckingham (the parish boundary follows the line of Padbury Brook or The Twins, a tributary of the River Great Ouse), and dates from the end of the 14th century and is the only surviving mediaeval bridge in Buckinghamshire. The parish division is marked by a boundary stone in the middle of the bridge.
The stone bridge is around long and wide, and spans the river by six low arches, with three refuges formed within the parapet on the south side.
The bridge is Grade I listed by English Heritage.