Phantasialand & beyond

Closest aiport to Phantasialand in Brühl is Köln/Bonn (CGN).
Closest international airports are Frankfurt/Main (FRA) or Düsseldorf (DUS).
Use www.bahn.de for domestic travels.
Likely best to use different airports for flying in to Germany and for departing from Switzerland.

Since this is a travel forum and not an agency I recommend to self-search other itineraries incl. Phantasialand in the forum, build your own one and ask for feedback on it in the forum.

What are your family's travel interests?

In Switzerland, the Bernese Oberland is a major target among Rick Steves fans, definitely worth considering. Bern, the gateway to the region, is around 6 train hours from Bonn. Have a look.

If your itinerary takes you there from Phantasialand, a number of interesting German destinations are near Bonn, in your path as you move south or close to it, and worthy of your attention:

Cologne
Middle Rhine Valley (old-world wine towns, castles, river cruises between Koblenz and Mainz)
Mosel River Valley (Koblenz > Trier)
Mainz/Speyer/Worms (Jewish historical/cultural sites, UNESCO World Heritage status)
Technik Museum in (Speyer)
The German Wine Route
Black Forest region
Towns on the German Half-Timbered House Route... Deutsche Fachwerkstraße

Hi, Cathy - Russ had some good tips for possible itineraries. I would also suggest that you buy multi-city tickets. For example, you could fly into Frankfurt and fly out of Zurich. From Frankfurt, if you are using public transportation, you can take the train to Brühl to visit Phantasialand. But since you are there, as Russ suggested, I would suggest visiting Cologne, which is an incredible city with a magnificent cathedral.

I will say that Munich is a bit out of your way. I would suggest after leaving Cologne to head down south towards the Black Forest. There are many charming places to stay, including Gengenbach (a charming town that is my personal favorite) or Freiburg im Breisgau (a university town in the Black Forest). Gengenbach would really suit your purpose, as it is small enough to be very walkable with scenic views, charming half-timbered houses and a nice variety of excellent restaurants and hotels. It has the added advantage of offering tourists who stay there a KONUS card, which entitles them to free public transportation throughout the region. I stayed for 4 nights and loved it. You can even take a day trip to Strasbourg, France, which is about a 30 minute train ride from Gengenbach.

Then it's a relatively quick train ride from the Black Forest to Switzerland, and if you get the multi-city flights, you can simply head to Zurich at the end, and save a lot of time and money.

I would encourage you to search this travel forum for posts about Switzerland, or even just go to the Switzerland forum and scroll through the posts for some that look interesting. That's what I do when I am planning trip. And of course, grab a guidebook and look through that for some ideas. :)

We want to visit one of the concentration camps. If we travel from Cologne,Germany, to Bern, Switzerland, is there one along this route?

"We want to visit one of the concentration camps."

The Osthofen concentration camp / memorial site is located in Osthofen just a 3-minute walk from the Osthofen rail station, which is just a 6-minute train ride from the Worms train station (I mentioned Worms in my previous post.) I have not visited Osthofen C.C. myself. But it's pretty easy to see how a visit there would fit quite well with a visit to Worms, where Jewish historical and cultural roots are memorialized and now recognized with World Heritage Status by UNESCO. See links below.

https://www.gedenkstaette-osthofen-rlp.de/fileadmin/gedenkarbeit/PDFs/Osthofen/Blatt_Osthofen_e.pdf
https://www.gedenkstaette-osthofen-rlp.de/osthofen/die-gedenkstaette/die-dauerausstellung/kz-osthofen

https://www.worms-erleben.de/experience/entdecken-und-staunen/kulturprofile/judentum/

Worms' Dom (cathedral) is one of Germany's premier Romanesque buildings. There's more to see in Worms too, as well as in nearby Speyer, but one has to read beyond Rick Steves' lightweight treatment of Germany in order to hear mention of these towns. Here's some Worms information from Tripadvisor:

https://www.tripadvisor.com/Attractions-g198632-Activities-oa0-Worms_Rhineland_Palatinate.html

I am not at all big on concentration camp visits. Of course, today, they are not concentration camps, just a few old buildings with displays, photographs, films, etc. They are still there today only as a reminder to the world - and especially to Germany - that the Holocaust really did happen. They are tangible places for German schoolchildren to visit during their impressionable teen years lest they misunderstand this important lesson and become Nazi-fans or Holocaust deniers. The goal is to hit visitors in the face with the gruesome details of Nazism, ethnic hatred, etc., none of which I need to revisit in order to understand what Nazis were about or to avoid becoming a Nazi-sympathizer or a Nazi myself. I came away with no nothing, basically, after my one concentration camp visit, with the exception of a bad stomachache.

Cologne, like Munich and Nuremberg, has a Nazi Documentation Center. It's housed in what once was a Gestapo Headquarters Building. See links below.

https://museenkoeln.de/ns-dokumentationszentrum/default.aspx?s=315

It gets positive reviews on Tripadvisor...

https://www.tripadvisor.com/Attraction_Review-g187371-d194327-Reviews-NS_Documentation_Centre_of_the_City_of_Cologne-Cologne_North_Rhine_Westphalia.html

Cologne has dozens of other things that might interest you as well:
https://www.tripadvisor.com/Attractions-g187371-Activities-oa0-Cologne_North_Rhine_Westphalia.html