At the bottom of the Osa fjord there is a cultural landscape marked by great contrasts; the wide terraces and the river delta at the fjord contrast with the steep hillsides in the background, where Norddalen leads up to the mountain. There are two farms here. Osa and Sævartveit – the farm at the river mouth and the hollow by the sea.
When the Etne water system was protected in 1994, preservation of the cultural landscape in Stordalen Valley was a a main objective. This is a valley with an exceptional abundance of Different types of plants and animals. In the grey alder forest in Stordalen there are more bird species than in most other places, in fact, denser than one tends to find in a tropical rainforest.