Back Cronfa Alwen Breton Alwen Reservoir CEB Cronfa Alwen Welsh Alwen-reservoaret NN Alwen Reservoir Swedish
| Alwen Reservoir | |
|---|---|
| Cronfa Alwen (Welsh) Cronfa Alwen Reservoir | |
 | |
  Alwen Reservoir | |
| Location | Conwy County Borough, Wales |
| Coordinates | 53°04′N 3°34′W / 53.067°N 3.567°W |
| Lake type | Reservoir |
| Basin countries | Wales |
| Max. length | 5 km (3.1 mi) |
The Alwen Reservoir (Welsh: Cronfa Alwen) is a 5 kilometres (3 mi) long reservoir near Pentre-Llyn-Cymmer in Conwy County Borough, Wales.