The longest bridge of the Ofotbanen Railway spans over a valley between Narvik and Riksgränsen. There was no topographic necessity for this bridge - it was built for strategic reasons since it could be destroyed easily in case of a foreign attack on Norway. However, the German attack on Norway in World War II came as a surprise. The Dynamite which had been prepared in several places along the bridge was still frozen. Only one load could be brought to explosion, enabling a relatively quick repair by the Germans (see white-coloured section at the right end of bridge). The railway track was moved Eastwards and the bridge taken out of Service in the 1990s. Ofotbanen is a section of the Malmbanen which links Lulea to Narvik; it was built for transportation of the iron ore from Kiruna in Sweden to the Norwegian harbour of Narvik.