Mt. Grímannsfell is the tallest mountain in Mosfellsbær District and pretty prominent in Mosfellsdalur although it suffers in comparison to the brightly coloured Mt. Móskarðshnúkar on the north side of the valley. This is a convenient way up to Stórhóll, the trail starts close to the Bringur ruins; this was a farm until the nineteen sixties. En-route you´ll see Helgufoss, as well as an unnamed waterfall on the slopes, and take in the beautiful view of Mosfellsheiði and the mountains west, north and south of the moor. There is a bridge across Kaldakvísl River but smaller creeks you must hop over on stones. The hike is suitable for most people who are in reasonable shape, but in winter you´ll need crampons, as it can get slippery. But there is always a chance you will see northern lights (aurora borealis) if you hike this route after dark in the winter.
Bringur Farm was inhabited from 1856 until the sixties. The farm was high up in the field, the barn ruins are visible below. The farm was sometimes called Gullbringur but Bringur was more commonly used. It became famous already in March 1857, when a group of fishermen travelling to their spring fishing grounds got caught in bad weather on the moor. Six of them perished but eight made it to Bringur, where they were nursed. Over a hundred years later, in 1974, the farm made the news again as one of the settings for a TV movie about the famous town magistrate Lénharður. The movie was quite controversial because its production costs went way over budget. In 2014, 18,6 hectares of the farmland were protected as a common area, to protect important natural and historical remnants and ensure public access to the area to enjoy the outdoors and learn about nature.
The Mosfellsheiði Moor is vast and east of Mt. Grímannsfell lay the main route to Þingvellir. In preparation for King Frederik´s VIII in 1907, the road was built up so it would be suitable for horse-drawn carriages. Since then it has been called The King´s Road and was used for cars once they arrived. Before the Alþingi Celebrations in 1930, a new road was built from Mosfellsdalur to Þingvellir and the King´s Road no longer used. However, it is still passable and today used as a riding and walking path.