Distance: 13-14 kilometres. Route: Kálfsárdalur – Grímubrekkur – Grímudalur – Upsadalur – Dalvík.
Maximum elevation: 930 metres. Hiking time: 6-8 hours.

Grímubrekkur slopes was the main route between Dalvík and the outer communities of Ólafsfjörður. You hike up into the Kálfsárdalur valley, which is well vegetated in some areas with a little lake in the bottom of the valley. You walk up from the farm Kálfsá and south of the Kálfsá river, which flows in its course just south of the farm. A hiking path lies up to the valley, and it was created when the telephone line to Dalvík had been set up there and it is very convenient to follow it while it lasts. Majestic mountains surround the valley, and to the east the highest one is Nítuhnjúkur mountain 955 m, and Hólshyrnu mountain to the west 853 m (also named Kálfsárhyrna mountain), one of the most well-formed mountains in Ólafsfjörður fjord. There are several cataracts along the river; the first is called Stórifoss waterfall and the next, Litlifoss waterfall. Kálfsáröxl is the name of the outer part of the valley. A short distance away is Ystanef tip, a grassy tip of land that protrudes into the river and there farther away is Fremstanef tip and between these is Laugahvammur dell with warm wells. Further in the valley there is a large hill called Hávaði and further away is a small lake, as has been mentioned. Now the pass lays before you where you pass through and Einstakafjall mountain is to the right. It is important to gain some distance when you hike into the valley before you ascend to the pass, owing to a large landslide located on the east side of the valley and which is very difficult to pass. The last stretch of the hike to the pass is steep, the landslide has been named Bröndólfsbrekka slope. When you get to the pass the Grímudalur lays before you, a small tributary valley out of Upsadalur valley and Böggvistaðadalur valley on the other side of Brimnesá river, also Eyjafjörður lays before you and the northern part of the town in Dalvík. From the pass, you can see Þröskuldur mountain to the west and people used that route for a short-cut between the outer areas of Ólafsfjörður and Dalvík. The route bears the name of the gigantess Gríma. The descent down to the valley through the Grímubrekkur slopes is rather steep. They are rock-ribbed in part but soon you walk on well-vegetated land. When you descend to Brimnesá river, it is possible to ford the river and walk the track along Böggvisstaðadalur valley (see Reykjaheiði heath, route no. 20) likewise you can walk along the Upsadalur valley, although there are not as easily passable trails until you get to the mouth of the valley.