| Name | Location | County | Country | Power source | Type | Function | River |
| Alwen Saw Mill, near Maerdy | Llandderfel | Merionethshire | United Kingdom | Water | Watermill | Saw mill | Alwen |
| Felin Uchaf, Llandderfel | Llandderfel | Merionethshire | United Kingdom | Water | Watermill | Fulling mill | Tributary to Dee |