We jumped on a train one Friday night and headed south (about 5 hours) to Vienna for the weekend. The weather wasn't very inviting but the city, museums, and coffee were. On Saturday morning we first went to the Belvedere Palace, which is divided into two parts (upper and lower) separated by a beautiful garden.
We only visited the upper palace which houses the “art around 1900” display. It includes a big collection of Austrian art including the world’s largest Gustav Klimt collection (The Kiss and Judith), and masterpieces by Schiele and Kokoschka. Here's the link: http://www.belvedere.at/jart/prj3/belvedere/main.jart?rel=en