Kateryna's flat was great. Not too far from the old town (about 30-40 minute walk) or right in front of the underground which takes you everywhere. The place is very nice and the kitchenette provides you with everything you will need. We loved how quiet the flat was. Kateryna was an excellent host and very cooperative. She left maps and guides of the city and gave us many tips on what to see near Vienna. I highly recommend this accommodation.