Karsten and Natalie are very friendly hosts. They gave us a perfect welcome in Berlin with a clean and cosy apartment, and a lot of informations about the best places to visit. The apartment is central and very close to metro and buses. The only thing that could be unpleasant is the bus that stops just in front of the apartment, but you won't care about it, if you will spend an entire week walking in Berlin... like us! Very recommended!!!