This interesting card gives you a good idea on how to sightsee Berlin, if you don't want or don't have enough time to walk around the city :) You can take the Bus 100 to see all the places depicted on this postcard. I've taken a sightseeing bus just once in my life in Brussels, but I still prefer the "traditional" way of sightseeing, even if I can't visit all the interesting sights this way :)
I read that the Bus 100 enters the Museum Island, which is a UNESCO site. I wonder, if any of the pictures on this card show buildings located on that island? I'm just curious if I can label this card as UNESCO :) I'll be very thankful, if you can help me :)
Berlin, nine times the size of Paris, is best explored on foot with the aid of the city’s excellent public transportation system. Of particular use to first-time visitors is bus line 100, a double-decker bus that passes by the major sights while connecting the two centers of this formerly divided city. Bus stops are numerous but for a good overview of the Mitte central district of Berlin take the bus all the way to the end terminus and alight at interesting sights on the way back.
You can read more about the route of this bus here, if you're interested in visiting Berlin :)