Nice waterfall along road 9 near Bygland/Vest Agder. The Heisfossen is not very spectacular but more the 100 meters high, according to the map. The visible part I have seen on a photo is about 25 meters high, probably from a distance there is a better view on the fall. There is a trail left of the waterfall that ends near the top of the fall but I am not sure if it is a good viewpoint.
Going south, just outside Austad the Reiarsfossen are much more impressive and higher. Nevertheless when driving near Bygland why not visit the fall.