From the airport:
Take the City Airport Train (CAT) or the train to Wien-Mitte/Landstraße, then the U4 underground line to Karlsplatz. Take the exit “Wiedner Hauptstraße”. 5-minute walk to the hotel.
From the Western Train Station (Westbahnhof):
Take the U6 to Längenfeldgasse and then the U4 to Karlsplatz.
From the Southern Train Station (Südbahnhof):
Take the tram line D to the Opera and then the bus line 59A to Schleifmühlgasse (2 stops).