Our stay in this apartment was wonderful. The apartment is great and everything was thought of. Karsten was away when we visited so his friend Sandra met us at the flat. Sandra was lovely, very helpful providing us with everything we needed. The location is great, a short walk from the Berlin Wall and very close to subway stations which go to the centre of Berlin. We rented bikes one day from a corner shop very close by which was great fun. Would definitely recommend this! Overall we thank Karsten and Sandra for a wonderful stay and definitely recommend this apartment to future Berliners.