Lake Åmänningen is Västmanland's largest lake after Lake Mälaren and Hjälmaren. It is located in Fagersta in the Bergslagen Engelsberg, one of Sweden's world heritage, as its nearest neighbor. The lake is the famous Oljeön with the world's only preserved oil refinery from the 1800s. Åmänningen is 2260 hectares with some 30 islands. The lake has plenty of pike, walleye and perch, and there is also trout and burbot.