at the end of August I'll be traveling by train from Brussels to Amsterdam. I expect to have already visited Brugge and Ghent. I was going to stop in Antwerp for a few hours but also thinking about Cologne Germany, though it's not really on the way. I'll only have a few hours. Once I get to Amsterdam I'll explore that region. Any suggestions?
Cologne is not really on the way between Brussels and Amsterdam; it would require a detour that could eat into your time (though I don't know what the travel times are).
In May I was in Belgium and the Netherlands and I spent some time in Antwerp, Rotterdam, Delft, The Hague, and Leiden, all of which are between Brussels and Amsterdam.
With just a few hours, I'd probably recommend Delft, which is a delightful walking-around town with a peaceful feeling.
Leiden is also a great town for exploring on foot. It feels a little more bustling than Delft, but still has a small-town feel. It's a university town with a noticeable student vibe.
If you're a fan of modern architecture, then consider Rotterdam. Rick has a good walking tour in his Netherlands guidebook, and you can also pick up a visitor's map with a good walking tour from the TI in the train station.
If you want to spend your time at one of the best smaller art museums in the region, then visit The Hague and go to the Mauritshuis.
Antwerp is also great, but I think it would be good to have more time to explore than just a few hours. I'd probably suggest it if you have most of a day at minimum. Still, there are certainly some things worth seeing there, even with your limited amount of time.
thank you Lane. I plan to visit some of the places you mentioned before this particular train trip. Thanks for your insight