| Bridge Name: | Thornborough Bridge |
| Carries: | Pedestrians (from 1974) A421 road (pre-1974) |
| Crosses: | Padbury Brook, tributary of River Great Ouse |
| Locale: | Buckingham/Thornborough parish border, Buckinghamshire |
| Material: | Stone |
| Spans: | 6 |
| Pierswater: | 3 |
| Length: | 30m (approx) |
| Width: | 4m (approx) |
| Open: | 14th century |
| Coordinates: | 51.9925°N -0.9394°W |
| Heritage: | Grade I listed structure |
Thornborough Bridge is situated on the original Bletchley to Buckingham road, now bypassed by a modern bridge in 1974 for the A421. The bridge is accessible to pedestrians from an adjacent lay-by.
The bridge straddles the parish boundaries of Thornborough and Buckingham, where the parish boundary follows the line of Padbury Brook (also known as The Twins), a tributary of the River Great Ouse. Dating back to the end of the 14th century,[1] [2] it is the only surviving mediaeval bridge in Buckinghamshire. The parish division is marked by a boundary stone in the middle of the bridge.[3]
The stone bridge measures approximately 30m (100feet) long and 4m (13feet) wide, spanning the river with six low arches.[4] Three refuges are formed within the parapet on the south side.
The bridge is Grade I listed by English Heritage.[5]