The Trollheimen Triangle traverses between three full service huts that form a triangle shape in Trollheimen ("home of the trolls") mountains, located in the middle of Norway. The huts are Gjevilvasshytta, Trollheimshytta and Jøldalshytta. The route can be run starting and ending at any of the three huts, and in any direction.
Between Trollheimshytta and Jøldalshytta, there are three trails: Svartådalen (the valley, fastest), Geithetta (over a mountain ridge) and Trollhetta (over a larger mountain, most difficult). The main route is over Geithetta.
The terrain varies between rock-hopping in the higher sections to easier dirt trails on the lower sections, and passes over one mountain (Geithetta) and a mountain pass (Mellomfjellet). It is typically done as a three-day hike.