At the end of Graben, in the very centre of the pedestrian area, on the corner of Kolh that leads to Hofburg and museums. This 'pension' is very well situated indeed. Above the shops, two floors of traditional Viennese rooms. Perhaps a bit noisy inside, but there is no outside traffic.
Service is friendly and breakfast pretty good. Not very expensive and you hardly need tickes for public transport. Shopping and terasses at the front door. With a lot of tourists, of course. We loved it.