Help! ONE day in Salzburg!

Hit up the Augustiner brewery/beer garden at Mülln.

I would recommend doing the castle tour. The views are spectacular and its and interesting tour. There quite SOM sites that you can see just walking around the city. I enjoyed the churches, St. Peter's Cemetery and the cemetery on the other side of the river. The latter was much less crowded with tourists. Pam

I would not try to squeeze Salzburg and the Eagles Nest in one day. Though it isn't a large city, a big part of the charm of Salzburg is in wandering around the town. You will curse yourself if you try to limit your time there to just a couple of hours. Though geographically nearby, getting to the Eagles Nest will take time. Access roads to the Berchtesgaden area are limited, and it is pretty hilly, so the road winds in many places, which slows you down. The roadway up to the Eagles Nest is unbelievably steep and VERY slow. Then there's the buses, the parking, getting tickets, and dealing with all the other tourists there.... if memory serves me, I think they only let so many in at a time. Its not a place you can just drive up to, jump out of the car, snap a few photos, say you've done it, and head on out. I would urge you to take an entire day for Salzburg, then drive over to the Eagles Nest first thing the next morning.

It can be done in one (long) day if you get an early start and leave late. It would be nicer if you could stay the night, but you don't absolutely have to. If you have a car, do Eagle's Nest first thing, you might be able to see it and be back in Salzburg by lunchtime. You don't have to stop in Berchtesgaden. It's pleasant but with limited time I'd go straight back to Salzburg. Then leave as late as possible (depending on your next destination/driving times)

For the Eagle's Nest, you want to drive to Obersalzburg. It is not in Berchtesgaden. Like the previous poster mentioned, you don't even need to stop in Berchtesgaden. You drive to Obersalzburg via a winding road and follow the signs to the Nazi Documentation Museum. There is a gift store/ticket counter where you purchase tickets to take a bus to the Eagle's Nest. In the same area is the Nazi Documentation Museum which, IMO, is very worthwhile. Renting the audio phones allows you to go through the museum at your own pace. However, allow a lot of time to walk through Hitler's bunkers at the end of the museum. Absolutely fascinating. You mention you are driving to Salzburg for a day trip. Where are you driving from? To thoroughly enjoy what you want to do/see, you probably need to stay one night. Have a great trip!

Thank you everyone for the advice. We will be leaving early morning from Garmisch to Salzburg. Really, I knew getting to Eagle's nest would be incredibly hard, but I figured I'd ask if it's possible since my brother wanted to go. I think we are going to end up skipping it due to time. Especially since it's just getting up there for photo opps.

Technically Heidelberg is considered to be in South Germany but yes, it's "northern" South Germany. It's 2 hours from Garmish to Salzburg. You could leave at 7 and arrive by 9, and leave at 7pm and get back to Garmish at 9pm. It's a long day but totally doable. If you're going in summer it will still be light out at 9 as well. With 10 hours, I think you have enough time to do a quick trip to Eagle's Nest (with or without a brief stop in the Dokumentation Zentrum) and still hit the highlights of Salzburg, but that's just me. I've done Salzburg as a day trip twice, once including the Eagle's Nest, and got to see the major sites in town both times. (Castle, Mozart's birthplace, graveyard, other SOM sites, churches, etc).