The road climbs 400 metres up the mountain in less than a kilometre as the crow flies. To handle that, engineers folded it back on itself again and again - 11 hairpin bends in total. Each bend is just wide enough for one car at a time, so traffic takes turns.
Right in the middle of the climb, the Stigfossen waterfall pours down beside the road. After heavy rain or snowmelt, it roars so loudly that you can hear it from the top. There is a little stone bridge that crosses the falls. Mist often soaks the road and the drivers.
Trollstigen was opened in 1936. It took eight years to build. The workers had to blast rock from the cliff face, sometimes hanging on ropes, to carve out a path. It is closed every winter because of snow and ice, and reopens each May when the snow finally melts.
At the top, there is a viewing platform that sticks straight out from the cliff edge. From up there you can see the whole valley, the waterfall, and the tiny cars far below crawling up like ants.