| Afon Merddwr | |
|---|---|
 Afon Merddwr at Pentrefoelas | |
  Location of the mouth within Conwy | |
| Etymology | Welsh for stagnant water |
| Location | |
| Country | Wales |
| Counties | Gwynedd |
| Physical characteristics | |
| Source | |
| • location | Mwdwl-eithin |
| • coordinates | 53°03′40″N 3°37′16″W / 53.061°N 3.621°W |
| Mouth | |
• location | River Conwy |
• coordinates | 53°02′42″N 3°42′25″W / 53.045°N 3.707°W |
| Length | 16 km (9.9 mi) |
Afon Merddwr is a river in the south of the county of Conwy, Wales. It is a tributary of the River Conwy and joins it near Pentrefoelas. It is about 10 km long.[1] "Merddwr" is Welsh for backwater or stagnant water, suggesting that it was named for its current or water quality.
- ^ Ordnance Survey Landranger Map 116 Denbigh & Colwyn Bay. Ordnance Survey.