Day trips from Salzburg

Will be in Salzburg for 3-4 days and think it may be just too many days in Salzburg alone so thought of doing some day trips. Would Hallstadt be a good choice or is that too far for a day trip. Any other suggestions would be welcome. Thanks!

Berchtesgaden? Prien and the Chiemsee? - yes I know both are over the border in Germany but both are less than an hour's travel

Several good things to do:

Visit the ice caves at Werfen and the old castle

Do a tour of a salt mine from either Austria or Germany

Take a boat ride on the Koenigssee for some of Germany's best Alpine scenery.

St Wolfgang is worth a visit the lake there is beautiful. Or any of the lakes around there

Would Hallstadt be a good choice or is that too far for a day trip.

Not necessarily too far...you can take the bus to Bad Ischl where you can wander around for an hour or so and then jump on the train to Hallstatt where a boat meets you and ferries the arrivals across the lake...

In fact, if you start early enough, you could stop off at St Wolfgang on your way and spend some time there before taking another bus to Bad Ischl and so on...

As #1 and #3- and others such as Innsbruck and Linz if you want to visit cities. Or Mondsee- nice town and the lake is pretty good too.

Hallstadt would be great.
I did it as an overnight trip and glad I did but you could definitely do it as a day trip (full day though) especially this time of year when there is so much daylight (the attraction of the place is the scenery so daylight would matter).

There are loads of options for half day bus tours too. The only one I did was to see a salt mine and that was pretty cool. There are plenty of others to choose from also.

Can anyone recommend any good tour company for a day tour to Hallstadt?
Thanks!