Katharina's place is a very homely and comfortable apartment to stay in to visit Vienna. It is right by the main city train station (Wein HBF) with it being only a 5 minute walk. In the train station there is also the U-Bahn lines where it takes a couple of minutes to get to the city centre, very convenient. There are also tram and bus lines right by the train station as well. There is everything you need for you stay in Kathi's apartment to be comfortable. Kathi herself is very friendly and helpful and made us feel very at home. I definitely recommend!