Hauptbahnhof station is the large-stop on the U2 line connects with the central trails station and the old city by the underground passage. Using this stop, you can easily reach any place of importance concerning the old city points of interest. It is also the best connecting stop if you are going to visit Nuremberg for one day on your way by night train to other cities of Franconian Germany.
A universal turn-by-turn route will quickly and cheaply bring you to the old city. You can use this route to get to the city center, to the train station and hotels in this part of the town. For those who like to travel by train and arrived at Nuremberg by flight, this route will help you to get to the central train station and, if you plan the train in such a way that you have 5-6 hours for the city, you can leave your baggage at the station in a luggage room and walk around the city.
Don't be afraid to get lost in new places!
