Yea, I just googled and it seems to be! It’s called Schloss Leopoldskron.

I have to be honest I only just watched Sound of Music for the first this year.
So I can’t recommend a tour, but I can imagine that they all cover the main stuff. Think there’s ones in big busses and ones in vans, maybe the van tour is better cos you can talk to the guide more directly.
For the Salzburg area I would plan 3-4 days but it depends on what else you’re interested in and your holiday style haha
It’s a really nice city to just walk around in and get lost in, I still love doing that. And I personally always plan in extra time for that when I go somewhere
And there’s lots of historical stuff to look at, but if that’s not your thing, then you probably don’t need to plan in much time for that. But if you do, that’s definitely a whole day or two if you don’t wanna stress around.
Hallstatt can also be a day trip from Salzburg, I’m pretty sure there’s tour busses that go there too. But then I’d add an extra day for that.