The oldest zoo in the world. All the usual suspects, plus the main draw: Giant Pandas. And if you've seen those 'No Kangaroos in Austria' t-shirts in all the tourist shops, you'll find out it's a lie ;)
Getting there: Tram 58 (7 stops, direction 'Unter St Veit') leaves from behind the hostel on Mariahilferstrasse, opposite Billa supermarket. Get off at "Hietzing". You can also get to / from here on the U4 U-Bahn line.
Entry is €18.50. But if you're feeling poor (and it's not too cold) you can often see the lions from the outside for free. Free lions! Happy days.