My flat is in the city center of Berlin, near central station and different museums. You can also have some good drinks at "Rosentaler Platz", it's 5 minutes with the tram. The next supermarket is 5 min away by walk.
The flat has around 35 m² and is on the 4th floor, without an elevator - you need strong legs ;)
I live in this flat less than one year, but you'll find everything you need for a comfortable stay in Berlin. You can use everything, but not my clothes. The commode next to the closet is for your luggage.
I'm sure you'll have a great stay in my cosy flat!