Such a beautiful city! The architecture and museums were the best I had visited on this entire trip.
I highly suggest you check out these in the Museum Quarter: Kunsthistorisches Museum (beautiful interior), Mumok (really interesting building and contemporary exhibits), and the Leopold Museum (great modern art collection).
While there I saw some great shows including Giacometti and Egon Schiele retrospectives, an expansive collection of Art Nouveau furniture and a priceless Goya exhibit. Let’s say I spent about 80% of my time in Vienna museums and it was so worth it!