Kolugljufur is the 2 km long and 20-25 m deep and beautiful gorge of River Viðidalsa. The ascending salmon does not get any further than to the waterfalls in the gorge.
The detour from road #1 is well worthwhile.
The gorge was named after the giantess Kola, a mythological legend, who lived there in a cave. More topographical names are connected to her.
Kolugljufur in Icelandic
North Iceland Saga Trail