The apartment is placed in the heart of the 5th-District. You only need 2 minutes to get to Naschmarkt where you can enjoy the best Falafel in town or drink a glass of wine (or two).
The U4-Station (Kettenbrückengasse) is one street from you and there are plenty of other buses (13A, 14A, 59A, etc.).
Also the Mariahilferstraße is in walking distance, same goes for Schloss Belvedere and it only takes a couple of minutes to get to Schloss Schönbrunn with the Subway (U4)