Martin's apartment was great! Didn't meet Martin but he was always contactable through mobile and email. His friend Fabian was waiting for us and helpful with giving local information. Martin had an info welcome pack waiting for us which we utilised. Size of the apartment was ideal for myself & my traveling friend. Nearest metro train station was across the road from the apartment. kreuzberg is within walking (15 minutes) distance. Less than 10 minutes walk to the bus stop that will take you to check point Charlie and the Berlin Wall. Happy to pay the cleaning fee as the appartment was very clean. Would definitely stay at Martin's apartment if I ever return to Berlin!