I live in Høylandet and find it interesting that you added Grongstadfossen on your website. I’m sorry that you didn’t know this when you visited the place, but there’s a better lookout place where you can see the whole waterfall from a much closer place.
The waterfall was also important during the industrialization because it was used to produce power for Høylandet’s inhabitants for several years. Unfortunately a big flood destroyed the whole thing.
Sorry for my bad english, just wanted to tell you =P