I believe the Marriott is near Potsdammerplatz in East Berlin. I think there is only one Marriott and it is very well located. The History of Berlin museum is in West Berlin and a distance away. You made a good choice staying in East Berlin as most of the historical areas are there. West Berlin has been rebuilt and looks exactly like the US. East Berlin has an interesting combo of ultra modern, communist, Fascist, and neo classic architecture.

Please write again and let us know how you enjoyed Berlin.