gaustatoppen is the highest mountain in the county telemark in norway which lies in the municipality tinn and hjartdal. the view from the summit is impressive, as one can see an area of approximately 60,000 km², one sixth of norway's mainland. the mountain is popular for downhill skiing in winter, and competitions have been held on its slopes. these competitions include the "norseman triathlon", billed as "the world's most brutal iron-distance triathlon". it starts in eidfjord and finishes at the top of gaustatoppen. the summit is accessible on foot in the summer, on a rocky pathway of medium difficulty, although the southern side of the mountain is very dangerous and inaccessible. the wreckage of an airplane crash lies there, as it is too difficult to remove it.