Nick H.
Google
This is really three museums in one, each being excellent. The Jugendstil/Modernist exhibition is very good and informative (the highlight I think); the technical museum is small, diverse and well presented. Then there is the castle museum, which besides lots of period furniture (most castles have) has two really interesting sections. There's one about nativity scenes made from wood, which was amazing (I'm not religious). This shows how important religion is/was here. Then there is a coin collection, which highlights how all traders passed through upper Austria. Again, I am not coin fan, but the range of coins and display was really interesting. Not a place for younger children and best avoid school groups if you can!
Ps. I didn't even know there was a natural history bit, but that sounds good too.