Here are some tips about what you could visit in Vienna for about 3 days:
- Stephan's Dome - in center of the city
- Aquarium
- Schonbrunn - you will need at least an entire day to visit it
- Hofburg Palace - great to see
- Motzart house
The best way to travel in Vienna is with the public transport, it's great and you arrive in time to all places you want to visit
Here are some pictures of this great city
AQUARIUM
A view of the city
HOFBURG
Stephan's Dome
Karlsplatz
Schonbrunn
For sure, there are lots of great places to see in this great city, but these were a few tips of what you could visit in 3, 4 days in this town.
Have a nice trip!