A short border river running through Kinlough and Tullaghan to the Atlantic between Bundoran and Ballyshannon, sharing its general basin character with the famous Drowes nearby. Limestone-backed and fast-clearing, the Duff receives early salmon and sea trout and is one of the opening-season options in the northwest. Small, with a concentrated fishing area, but the proximity to the Melvin-Drowes catchment gives it a regional legitimacy that larger visitors sometimes overlook. Local club access. Not to be confused with the Duff Water further north.
- Limestone