Vienna is famous for it's cuisine as well. One of these institutions is the Sachertorte.
This example is from Demels. There's a whole story of the legal battle between this cafe and the Hotel Sacher about who owns the "genuine" sachertorte recipe. The truth is, whilst it's a nice cake, it's just not as good as having a decent slice of mudcake! progress marches on!
Much more satisfying and a whole lot more comfortable and satisfying is going to a Beisl. Typical Viennese fare centered around the fried and the boiled.