We arrive in munich on the evening of 19 July. We are flying out of munich on the afternoon of 26th july. I have booked onto a free walking tour on the morning of 20 july. We would like to visit Dachau concentrated camp but maybe just for a half day your and would also like to visit Vienna
for a couple of days taking on a classical concert. We would also like a day tripto Salzburg.
What's the best way to do this? That is, is it best to do a day trip from Vienna to Salzburg or from Munich?
Sorry all the questions but as it's only a week we want to make the most of our time
Thanks

Such limited time... too bad you didn't choose to fly out of Vienna and save yourself the trip back to Munich.

You could find out if there are places to store luggage at Salzburg train station and make a quick visit while traveling between Munich and Vienna... another option would be to spend a night in Salzburg on the way to Vienna, so that would be 3 nights Munich, 1 Salzburg, 3 Vienna, last night Munich.

If you want to do a day trip you can check out this link: https://reiseauskunft.bahn.de//bin/query2.exe/en
I imaging Munich > Salzburg is the shorter train trip if you do a day trip but personally I'd rather avoid the back and forth thing as much as possible since you're already back tracking to Munich.

Whatever you choose, enjoy your time!

for lots on trains check www.seat61.com; BETS-European Rail Experts and www.ricksteves.com

There are two competing train companies in Austria www.oebb.at - Austrian Railways and Willkommen which competes on main routes and cn be cheaper than www.oebb.at.

Salzburg is a short train ride from Munich - do it as a day rip and then you won't have to spend time relocating.

Your flight arrangement is incompatible with the ground itinerary. The best arragement would have been to fly to VIE and return from MUC, or fly into MUC and return from VIE. Short of this, the next best would be to travel straight to Vienna upon arrival at MUC depending on what you mean by "arrive in munich on the evening of 19 July." If you can take an S-Bahn into Munich Ost station at 19:23, you can make subsequent train connections to reach Vienna by 00:33 mid-night. If you can take the 23:35 night train from the Munich Ost, you get to Vienna in the July 20 morning at 6:35. Both avoid second checkin-out cycle in Munich. By having to do backtrack and an additional hotel check-in/out cycle, you have thrown away at least 10% of your available trip time right off the bat.

>>> is it best to do a day trip from Vienna to Salzburg or from Munich?
Look at the map and www.bahn.com for train schedule. Salzburg is closer to Munich in distance and in time. It makes no sense to do Munich-Veinna, then Vienna-Salzburg-Vienna, then Vienna-Munich.
If you do want to visit Vienna and Salzburg, make Salzburg a layover stop. Munich-Vienna, then Vienna-Salzburg-Munich. They have luggage lockers at the Salzburg train station.
Dachau takes about 5 hours total from Munich. One hour each to go there and back and 3 hours to spend time there.