Sieg Railway
Au (Sieg) station is a railway junction in the town of Au in the municipality of Windeck, which is in the German state of North Rhine-Westphalia. It lies on the Sieg Railway to Siegen, where the Engers–Au railway branches off to Altenkirchen, where it connects with the Upper Westerwald Railway ("Oberwesterwaldbahn"). Despite the town’s small population, the junction station is important for commuters from the districts of Altenkirchen, Neuwied and Westerwaldkreis for its connections towards Siegen, Cologne, Bonn, Düsseldorf and Aachen.