Hallstatt with a day trip to Salzburg?

Of the two, Hallstatt or Salzburg, I would much prefer Hallstatt, but maybe that's just me.

In 2002, I did Salzburg as a day trip from Munich and saw about everything I wanted to see (Mirabell, the Altstadt, Hohensalzburg, Nonnenberg Abbey).

In 2009 I spent two nights in Hallstatt. It doesn't take long to see Hallstatt, but I really just loved being in Hallstatt, enjoying the scenery. I had lunch on the porch of a restaurant on the Marktplatz. I went up the incline, but just enjoyed the view of the lake from Rudolfsturm; I didn't bother to go to the salt mine.

But doing either as a day trip will require a lot of backtracking. If you go into Salzburg from Hallstatt, it's about 2 hours back to Hallstatt or on to Munich. I think I'd go from Hallstatt to Munich with a stopover in Salzburg. There is a bank of locker at the Hbf in Salzburg. Store you luggage there while you spend the day in Salzburg.

I agree with Lee. A stopover in salzburg is perfect.
Hallstatt is so beautiful and relaxing, but if that is not u then sounds like Salzburg is the answer over hallstatt.

If you have not seen the Eagle's Nest, the Konigsee and the Berchtesgaden Documentation Center and they are not on your Itinerary I would stay in Salzburg. That way you can do day trips to Hallstatt and Berchtesgaden, and see all three places/areas efficiently.

How much time would it take to see the Eagle's Nest, coming and going from Berchtesgaden? Is this a super long day all by itself, or could you see that plus the Konigsee in the same day? Or would another place be better to stay?

I would say that you could see the Eagle's Nest, Documentation Center and the Konigsee in one very rushed day with an early start. You should really allow half a day for each one. If visibility is poor I would skip the Eagle's Nest and do the Documentation Center. (The bus for the Eagle's Nest leaves from the Doc Center parking lot, or near by). The Konigsee also is best seen in good weather but is not as dependent on good weather as the Eagle's Nest. So, if the weather is good, and you only have one day I would skip the Doc Center.

This Doc Center focuses on the acquisition of most of the land in the Berchtesgaden area by Hitler and his buddies. Its exhibits differ from the similarly named Doc Center in Nuremberg. Some of the bunkers used to protect the Nazi command are still accessible from the B'gaden Doc Center.

Note that the Eagle's Nest usually is closed from October to May of each year. The exact dates depend on the weather.

Hallstatt is quite pretty. Not sure I'd want 3 nights there - 3 hours might be enough, actually.

Guests in Berchtesgaden get a free visitors card, which is valid for free local bus transport. The special bus from the Documentation Center to the Eagle's nest isn't included, but you should get a discount on this fare with the visitors card, according to this informational flyer (p. 3-4 in English.) You also get a discount on the bus to Salzburg.

But Berchtesgaden isn't a great base town for visiting Hallstatt.