Question: top 20 things to do in vienna?
Answer: Schönbrunn Palace. Source: flickr. ... 
Hofburg Palace. Source: flickr. ... 
St Stephen's Cathedral. Source: flickr. ... 
Schonbrunn Gardens. Source: flickr. ... 
Rathaus. Source: wikipedia. ... 
Tiergarten Schonbrunn (Vienna Zoo) Source: flickr. ... 
Belvedere Museum. Source: flickr. ... 
Vienna State Opera.