Fagrifoss on the Kaldakvísl River is certainly much more popular among fishermen than tourists. The area and the views are not particularly stunning, and you should definitely not confuse this waterfall with another Icelandic waterfall of the same name, Fagrifoss, located in southeastern Iceland.
Fagrifoss on the Kaldakvísl originates near the F26 road. Turn off here (GPS: 64.300479, -18.980435) to the west and drive for about 2 kilometers.