| Llyn Alaw | |
|---|---|
 | |
  Llyn Alaw | |
| Location | Anglesey, North Wales |
| Coordinates | 53°21′10″N 4°24′50″W / 53.35278°N 4.41389°W |
| Type | Reservoir |
| Basin countries | United Kingdom |
| Max. length | 4.3 km (2.7 mi) |
| Surface area | 3.6 km2 (1.4 sq mi) |
| Max. depth | 5.2 m (17 ft) |
| Water volume | 1,640×106 imp gal (7.5 GL; 6,000 acre⋅ft) |
| Site of Special Scientific Interest | |
| Location | West Gwynedd |
|---|---|
| Interest | Biological |
| Area | 353.63 ha (873.8 acres) |
| Notification | 1968 |
Llyn Alaw (meaning: Lily Lake) is a man-made reservoir on Anglesey, North Wales managed by Dŵr Cymru Welsh Water. It is a shallow lake and was built in 1966. It is a Site of Special Scientific Interest and a destination for over-wintering birds.