| Name | Location | County | Country | Power source | Type | Function | River |
| Gellidywyll Mill, Bont Dolgadfan | Bont Dolgadfan, Llanbrynmair | Montgomeryshire | United Kingdom | Water | Watermill | Corn mill, Fulling mill | Twymyn |
| Penybont Mill, Bont Dolgadfan | Bont Dolgadfan, Llanbrynmair | Montgomeryshire | United Kingdom | Water | Watermill | Woollen mill | Twymyn |