half day trip from Salzburg
 

I am planning to make a half day trip from Salzburg and trying to choose between the following options:
- Hallein Salt Mine and Königssee
or
- Berchtesgaden Salt Mine (no plans to visit Eagle's Nest) and Königssee

I do realize that Berchtesgaden is geographically closer than Hallein to Königssee. Should that be a decisive factor?
We will have a car so getting to either place shouldn't be a problem.
I would appreciate your advice.
Thanks!

FWIW, I found Hallein fascinating and visited it by public transportation. I didn't see the other places you are considering.