Krakow to Brussels - where to stop along the way?

If you really want to take the train all that way, with so little time, instead of asking, "Where should I stop?" I'd instead look for the most logical train routings between Krakow and Brussels and see where you'd change anyway. For example, one quick check shows a train with connections in Poznan, Berlin, and Cologne. So do you have any interest in any of those places? Berlin would be an easy choice.

As much as I love train travel, with only four days, I probably would fly to Brussels and spend time in Bruges and Ghent, personally.

If you enjoy cities, I'd consider Berlin. We also really enjoyed Dusseldorf. Both have excellent train connections.

My first thought was Berlin and it does make sense if you're taking the train. That would be my choice unless you've already been to Berlin and want somewhere different.

Thanks for your replies so far. I recently spent 7 days in Berlin and was hoping to see some new territory. The train connection does look good out of Berlin to Brussels. I have my hotel reservations for 6 days in Brussels and will be spending 9 days in Reims before flying out of Paris.

It is a long ways from Krakow to Brussels!

Frank

Nine days strikes me as a painfully long time to spend in Reims unless you're using it as a base and planning to travel back and forth to Paris often (utilizing the rail pass).

It looks like either way you slice it, it's going to be some long days on the train.

My first thought was Berlin as well, but since you've been there recently, what about Dresden? It's a compact enough city that I think you could see most of its attractions in a few days. There's also the option of doing a day trip to Leipzig or Görlitz, or both. The Meissen factory is an S-Bahn ride away and an interesting way to spend an afternoon. The problem is Krakow-->Dresden is 7h45m with one stop in Wroclaw, or as high as ten hours with a stop in Prague (this is because the Krakow-->Prague train makes 15 intermediary stops. One the plus side, you'll see a lot of the Polish and Czech countryside!). And then Dresden-->Brussels is going to be 8h15m (transfers in Leipzig and Frankfurt) or more. However, in playing around with the DeutscheBahn website, that looks like the shortest time spent on a train.

Another train route would go Krakow-Vienna, 6 1/2 hours with 2 train changes. Vienna-Frankfurt, 6 1/2 hours on a direct train. Frankfurt-Brussels, 3 hours on a direct train. Also, if feeling adventurous, NightJet from Vienna to Cologne, then direct train to Brussels in 2 hours.