My wife and I will be passing through Vienna on our way to Venice in June. Our train arrives around noon at Sudbahnhof station. The train to Venice leaves from Westbahnhof around 8:30 pm.

If I'm reading the metro map correctly we will likely take the U-bahn to Stephansplatz and switch lines to Westbahnhof. Since we'll be in the circle, we'd like to see a sight or two (art and architecture preferred) and maybe have a bite to eat. It will be a Sunday afternoon and we will each have a suitcase in tow.

It's our first time to/through Vienna. Any tips for stashing the suitcases would be appreciated as would any suggestions on where to go in such a limited time.

Thanks

Well if you want art I'd definitely recommend the Kunsthistorices! It's the biggie.

Most train stations usually have some kind of luggage accomodation. I would start there and/or contact a tourist office in Vienna by e-mail if you want further information.

Your best bet is probably going to Westbahnhof first and leave your suitcases there, before heading back into town.

I think you'll probably will have time to tour the Hofburg Palace, check out St Stephen's Dom, and drop by the Kuntshistoriches Museum (KHM) - the Bruegel paintings there is a MUST SEE!

and don't forget to go to Demel for the best cakes in Vienna.

Great. Thank you all for the speedy answers! So with your advice, our plan would look something like this:

Arrive Sudbahnof around noon.
Buy the 24 hour pass for U-bahn?
Head to Westbahnof and check bags or find lockers. Jump back on the U-bahn and head for the Herrengasse stop.
Demel for lunch.
Walk or ride to the Hofburg Palace and Kuntshistoriches
Back on the Ubahn to Westbahnhof.

How early should we get back to the train station to collect bags and board the night train to Venice?

If you have time, take Tram #1 or 2 and go around the Ringstrasse. Both take the same route but in opposite directions. One "roundtrip" takes about 30-mins. Great way to sightsee the city (you can see many great buildings of the city along the Ringstrasse).

Thanks yk. Is the Ubahn ticket good for the tram to or are they ticketed separately?

I'm afraid I don't know the answer. When we were in Vienna we didn't buy any transportation pass.

I'd assume a 1-day pass should be good for ALL types of local transportation, but hopefully others here can answer more definitively for you.