Much of the sand and gravel that the town of Etne is built on was laid down at the end of the Ice Age and is evidence of melting glaciers and roaring meltwater rivers. The uncompacted material in the big terraces leave their unmistakeable mark on the wide elongated valleys.
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.
In Skånevik there are marks left from the ice edge that advanced during the thousand-year cold spell (Younger Dryas) that marked the end of the Ice Age roughly 11 500 years ago. The glacier first proceeded out into Åkra Fjordand and around Vannes and thereafter sent an arm in toward Skånevik. Here, the glacier lay down an end moraine up against the mountainside.