Vänern, Western Europe's largest lake has a maximum depth of 106 m and an average depth of 27 m lake is the deepest depression in a flat bedrock landscapes, which also explains the diversity (about 22 000) of the scenic islands, islets and reefs. The shoreline is about 20 mil long. The lake surface, covering 5 648kvkm, swim 35 different species of fish, making the lake to Sweden's richest. It also reveals that many sport fishing techniques can be practiced in the lake.
Vänern was originally a bay of the North Sea. Vänern, consisting of current Dalbosjön and Värmlandssjön , was formed by uplift when the ice last retreated , ie about 9000 years ago. When Vänern through uplift separated from the sea became populations of Atlantic salmon ( Salmo salar) and brown trout (Salmo trutta) trapped in the lake.
The trouts and salmons adapted to living their entire life cycle in freshwater. Vänern many tributaries became their spawning rivers. Such freshwater relict populations of Atlantic salmon are worldwide very rare. Gullspång Salmon - the world's largest landlocked salmon can weigh over 20 kg. Every year there are caught salmons and / or trouts weighing more than 10 kg. Nowhere in Europe is probably easier than Vänern catching a salmon in the 5- pound class ! The most important salmon rivers are Klarälven and Gullspångsälven.