Hi, I will be heading to Frankfurt later this week. I have also purchased 4 day rail pass for unlimited travel. Any good ideas about day trips?? Thinking about Bonn, Cologne, Dusseldorf, Heidelberg, etc.---Hamburg and Dresden are far and too ambitious for day trips!
G
What about the middle Rhine - Bacharach, St. Goar, etc? Unfortunately, you didn't need to purchase a rail pass for that short trip. I think I Heidelberg would be a good place. If it were me, I think I would try the Northern Black Forest. Start in Pforzheim and go up the Nagold river to Calw, a very small, mostly fachwerk village, hometown of Herman Hesse. Then go farther, to Freudenstadt, called the capital of the Northern Black Forest.
For Day trips from Frankfurt, consider Wuerzburg, Buedingen, Seligenstadt, Aschaffenburg, Marburg, Idstein, or Bad Homburg. These are all rather close to Frankfurt, so a pass wouldn't be needed really. To make use of a pass, you might want to head down to Stuttgart and Tuebingen, or Regensburg. Even Munich is only 3 hours away with the ICE. The Rhine is also a good choice, and you can ride up and down both sides of the river, seeing about 40 castles in 1 day.