Amsterdam to Germany to Paris

I would eagerly spend two days in Cologne. There is much to see there.

Research the 'sights' and 'attractions' before you go to be sure you don't miss something of interest to you.

The train ride to Cologne will be interesting for you.

Nearby Aachen has some interesting history as well.

I've done a similar route via train - a stop in Cologne to visit the Cathedral is worthwhile (it's right by the station), but I don't think it's worth a couple of days. You could continue up the Rhine to Koblenz, then switch trains and continue to Trier. Trier is a former Roman settlement with lots of history. As it's on the banks of the Mosel River, it's in a pretty setting and is small enough so you can walk to most places of interest. From Trier to Paris, you could go via Luxembourg City which is well worth a visit. The train route goes along the Rhine and Mosel Rivers much of the way and you'll see many castles on the hilltops of both rivers.

In two days you could easily visit Koln and Bonn or you could spend a day on the Rhine or Mosel Rivers.

I think Tim's on the right track. Here are my suggestions for a quickie 2-nighter:

Day 1) Get an early start. Amsterdam-Cologne. The city center and sights are compact. Spend several hours, have a meal. Train to Koblenz for overnight near the station.

Day 2) Stow bags at station or with hotel if close enough to station. Train to Marksburg ( www.marksburg.de ) for a tour of the Rhine's best-preserved medieval castle. Train back to Koblenz and on to Trier for overnight. Stay near the town square, see some sights that afternoon and evening and the next morning before moving on to Paris.

Thanks for the replies. These are all good ideas! It looks like I have some viable options to see a little bit of Germany on my trip!

We stayed in Aachen and Trier.....very interesting towns.