From the West Autobahn junction at the Salzburg suburb of Wals-Siezenheim near the German border, the motorway runs southwards through the Salzach Valley between the Berchtesgaden Alps, with the Untersberg massif to the west and the Salzkammergut Mountains to the east. The first tunnel is at Golling in the southern Tennengau, where the Salzach breaks through the Tennengebirge. It passes Hohenwerfen Castle and reaches Bischofshofen in the Pongau district, then turns eastwards along the Salzburg Slate Alps to Eben and again southwards to Altenmarkt in the Enns Valley.