The 13km day-hike to Bifröst follows one of the country’s best salmon rivers: the Norðurá. Originating high on the moors of Holtavörðuheiði south of Brú, the river flows southwest to meet up with western Iceland’s biggest river, the glacial Hvítá, at the head of Borgarfjörður where it finally empties into the sea. From Varmaland, you follow the river upstream: head north along Route 527 to Einifell farm, where the road downgrades into a jeep track as it heads to a T-junction west of Höll farm. From here, head west around the foot of Hallarmúli hill (260m) towards the Laxfoss waterfalls in the Norðurá. Continue past the abandoned farm, Veiðilækur, on to the farmstead at Svartagil and the Glanni waterfalls. Here you pick up Route 528 and fork left, crossing the Norðurá and Bjarnardalsá rivers, over the Grábrókarhraun lavafield to join the Ringroad a kilometre or so east of Bifröst.