need help with itinerary

Getting from Berlin to Munich will take at least half a day. Do you really have two days, or is it two nights (one and a half days there)? If the latter, then you've already filled your whole time with Dachau and Neuschawanstein day trips.

Perhaps it would be best to continue on your previous post:
https://community.ricksteves.com/travel-forum/germany/need-help-with-itinerary-6-days-in-hamburg-at-christmas

Two easy day trips from Hamburg: Lübeck, 44 min train ride; Bremen, 60 min train ride.
Keep in mind the shorter days/hours of daylight.
If interested in emigration, there is a very interesting museum in Bremerhaven, just north of Bremen.
Deutsches Auswanderer Haus.

Hi,

Neuschwanstein Castle (in the town of Füssen) is an 1 1/2 hour drive from Munich. And there is quite a hike up a very steep hill to get into the castle, as I recall from my 1992 visit. So you will want to allow enough time to do that and enjoy the tour. We had driven down from Landstuhl, saw the castle (maybe took 3 hours?) and drove up to Munich afterwards. But that was summer, so the days were really long. We have been to Germany in the winter as well (in the Landstuhl area), and it gets dark very early (around 4 or 4:30) so you will want to plan accordingly.

We also visited Dauchau Concentration camp in 1992 also. It is about a half hour from Munich. As I recall, it didn't take very long to see; maybe about an hour? But that was a long time ago and they may have more extensive exhibits now.

Hope your visit goes well!

"Finally we have 2 days in Munich In Munich we would like to visit Dachau Concentration camp and Neuschwanstein castle"

6 days in Hamburg and 2 days in Munich?? It sounds like you won't even have 2 days there once you include the ground travel, and that your precious little time will be spent outside Munich. This long trip to Munich is absolutely unnecessary. Neuschwanstein is a full-day's outing from Munich pretty much for a 30-minute tour. And it's a modern structure with a fake castle facade - not a genuine castle. Your time in Berlin (3 nights) is already too short! But you could perhaps visit Sachsenhausen concentration camp on a short outing from there. And a trip out to Potsdam's Sanssoucci palace provides a much much better tourist experience than N'stein and is quite easy from Berlin.

"6 days in hamburg so would like to do some suggested day trips."

Lüneburg is a delightful place and only half an hour from Hamburg. Here is a day trip guide.

I would switch 2-3 days earlier to Berlin. Much more things to do.

Do you need to go to Munich? 2 days is not a lot of time, and you lose half a day when you travel from Berlin to Munich. Sure, you would miss Neuschwanstein, but there is a fairytale castle between Hamburg and Berlin: Schwerin castle. And close to Berlin is Sachsenhausen concentration camp. I would also recommend to spend more time in Berlin if possible.