Great place to stay in close proximity to the U-Bahn stop Schwartzkopffstraße -- three stops from Friedrichstraße with all the connecting lines. The flat is located in a very quiet part of town and offers a nice view across a canal and over to Berlin Mitte.
It is a very clean space with all you need -- perfect place for two people.
Franzi is a very nice, communicative host who was always available through messages when we needed something. She also provides some maps, guides and tips for people who don't know the city.
We would definitely stay at this place again!