From Sarn Mellteyrn, Gwynedd to all cities in Hertfordshire starting with letter F
- Felden, Gwynedd
- Fiddlers Hill, Gwynedd
- Fields End, Gwynedd
- Fishers Green, Gwynedd
- Flamstead, Gwynedd
- Flamstead End, Gwynedd
- Flaunden, Gwynedd
- Fleetville, Gwynedd
- Friars Wash, Gwynedd
- Frithsden, Gwynedd
- Frogmore, Gwynedd
- Frogmore, Gwynedd
- Frogmore End, Gwynedd
- Furneux Pelham, Gwynedd