Marsanafossen (officially written as Marsånafossen) is a big waterfall at the Oppstrynsvatnet (along road 5), near Flostranda in the region Sogn og Fjordane.
The river Marsåna is one of the more voluminous rivers coming down from the mountains at the Oppstrynsvatnet. Almost at the end the river makes a drop of appr 225 meter over two stages, just before it flows into the Oppstrynsvatnet. The biggest drop (the lower part is a single drop of 95 meter).
It is strange that the waterfall isn’t mentioned on maps and that there is a waterfall in the river east of the Marsånafossen called Russefossen. But this waterfall isn’t visible from the roadside.
There is a parking along road 5 where you will have a good view on the Marsånafossen directly on the other side of the Oppstrynsvatnet.