This was a very nice apartment that's a 5 minute walk to Potsdamer Platz, and a 5-10 minute taxi ride from the main train station. The apartment is very easy to find, on the ground floor facing a central courtyard right next to Heidi's family's apartment. They walked us through everything upon arrival, and everything was very clean and they have piles of maps and brochures for sightseeing. We rented bikes from the hotel 50m to the right as you leave the apartment, and they were a great way to see a lot of the city in one day. The location is very central to a lot of sights. Highly recommended!