The principal of these two rivers, Österdalälven, begins where the Storån and Sörälven meet, near Idre [REF].
After the junction of the Österdalälven and Västerdalälven, the river heads east, passing Borlänge, Dalarna's largest city,[REF] then receiving the waters of the Lillälven, itself fed by the Faluån, a river which goes through Falun, Dalarna's second largest city [REF].