During the Viking Age, Birka  listen (help·info) (Birca in medieval sources), on the island of Björkö (literally: "Birch Island") in present day Sweden, was an important trading center which handled goods from Scandinavia as well as Central and Eastern Europe and the Orient. Björkö is located in Lake Mälaren, 30 kilometers west of contemporary Stockholm, in the municipality of Ekerö. The archaeological sites of Birka and Hovgården, on the neighbouring island of Adelsö, make up an archaeological complex which illustrates the elaborate trading networks of Viking Scandinavia and their influence on the subsequent history of Europe. Generally regarded as Sweden's oldest town, Birka (along with Hovgården) has been a UNESCO World Heritage Site since 1993.