The Tauern Railway Tunnel (German: Tauerntunnel) in Austria is the longest tunnel of the Tauern Railway crossing the main chain of the Alps. Currently, it has a length of 8.371 kilometres (5.201 mi). The highest point of the tunnel, which is also the highest point in all of the railway line, is at 1,226 metres (4,022 ft) above sea level. The tunnel's north entrance is at Böckstein in the valley of Bad Gastein in the state of Salzburg, while the south entrance is near Mallnitz in Carinthia.