I'm working on a blog post about the persistence of Confederate monuments in the southern U.S. and how they could be better contextualized. How were Nazi symbols in public places treated following WW2? Are there examples of some being torn down and others left? Were historical placards placed around those that still stand?
My brother-in-law is currently stationed in Germany and visited the Nuremberg rally grounds. He said there are plenty of places where you can see the mountings for swastikas, Nazi eagles, and other stuff, but the symbols themselves are long gone. He has pictures, but I don't want to share without his permission. I know this only answers your question about one site, but I hope it helps.
Oh, and I almost forgot - the Eagle's Nest in Berchtesgaden (Kelhsteinhaus) is still there (one of the only Nazi buildings left in Berchtesgaden, if I remember correctly). It's now a restaurant/hotel/tourist spot, but to book a tour, you have to use an on-location guide; this is to prevent tours run by neo-Nazis or sympathizers. Some of the historical rooms, complete with Allied graffiti and damage to the fireplace (soldiers chiseled off parts of the marble as souvenirs), are all behind glass and you can only see them on a guided tour. The restaurant and view of the Alps are played up, though the site (http://www.kehlsteinhaus.de/en/) doesn't deny the history.