Siegen is well connected by rail. The main station (Siegen Hauptbahnhof) has direct trains to Cologne (about 1.5–2 hours on the RE9 regional express) and Frankfurt (about 1.5 hours on the S-Bahn via Dillenburg). Services to Dortmund via Hagen take around 1.5 hours. The station is in the valley below the old town, about 15 minutes' walk from the Lower Castle.
By car, the A45 motorway passes through the Siegerland valley, making Siegen easy to reach from the Ruhr area to the north (about 1 hour to Dortmund) or Giessen to the south. The city is about 2.5 hours from Frankfurt and 1.5 hours from Cologne.