| Coedydd Dyffryn Alwen | |
| Aos: | Clwyd |
| Interest: | Biological |
| Coordinates: | 53.0165°N -3.49°W |
| Displaymap: | Wales |
| Area: | 42.82 ha |
| Notifydate: | 5 February 2003 |
Coedydd Dyffryn Alwen is a Site of Special Scientific Interest in the preserved county of Clwyd, north Wales.
It contains a mix of different woodland types, reflecting the underlying geology and soil type, including ash, oak and rowan, with a hazel understorey, with a rich ground flora including globe flower, oak and beech fern.[1]