hot springs in austria?

I haven't visited that one in particular, but I have experienced one near the Neusiedler See, southeast of Vienna:

St. Martins Therme

These types of places are fairly common in Germany and Austria. It's usually not a true hot spring, just heated water, which may or may not come from a mineral spring.

Therme are everywhere in Austria. There is even a popular one in Vienna called Oberlaa. It is the kind of things that Austrians do a lot, but won't make the list of a casual traveler.