| River Dun | |
| Name Other: | Bedwyn Brook |
| Subdivision Type1: | Country |
| Subdivision Name1: | England |
| Subdivision Type3: | Counties |
| Subdivision Name3: | Wiltshire, Berkshire |
| Subdivision Type4: | Districts / Boroughs |
| Subdivision Type5: | Towns |
| Subdivision Name5: | Great Bedwyn, Hungerford |
| Length: | 16km (10miles) |
| Source1 Location: | Great Bedwyn, Wiltshire, United Kingdom |
| Source1 Coordinates: | 51.3711°N -1.6066°W |
| Source1 Elevation: | 120m (390feet) |
| Mouth: | River Kennet |
| Mouth Location: | Hungerford, Berkshire, United Kingdom |
| Mouth Coordinates: | 51.4122°N -1.494°W |
| Mouth Elevation: | 90m (300feet) |
The River Dun (historically known as Bedwyn Brook) is a tributary of the River Kennet, flowing through Wiltshire and Berkshire in England.[1] Its main source is in the parish of Great Bedwyn, Wiltshire and it flows 16km (10miles) in a northeasterly direction into Berkshire. It discharges into the Kennet at Hungerford,[2] [3] which has a smaller average flow and width upstream of that point.
The Dun valley is an important transport route through the high chalklands between the London Basin to the east and the Vale of Pewsey to the west. It is the route by which the Kennet and Avon Canal (linking London and Bristol) enters the Thames basin from the Vale of Pewsey, crossing the watershed with the aid of the Bruce Tunnel and Crofton Pumping Station. The later Reading to Plymouth railway linking London and the south-west also follows the valley.
The Dun has two named tributaries: the Froxfield Stream joins on the left between Little Bedwyn and Hungerford, and the Shalbourne Stream on the right above Hungerford.[4] During or after the building of the Kennet and Avon Canal in the late 18th century, the Shalbourne was diverted into it. In 2000 the stream was returned to its original course, rejoining the Dun via a culvert under the canal.[5]