Regensburg is a good choice to hop off the train and see a pleasant Bavarian town. However, a short bus ride away is the marvel of Walhalla - a hall of fame for the German speaking world.
This stroll takes you down to the river where you can join the locals sipping local wines on the bridge.
A bus ride to Walhalla is well worth the detour to see German history in the round, all told through the people thought to be worthy of being in the hall.