It's a nice small flat in the very center. You have about 20 min walk to the Opera, and by public communication is easy to get everywhere really fast- so it's a perfect location for a tourist event for a longer stay. In the apartament Walter left as a leaflet with all the important info (rules and important number and adresses in Vienna). When needed, we always could use his help by phone. In general - a nice, comfortable place with a good, friendly host:)