Originally Posted by
UKtravelbear
Take the S or U Bahn and explore yourself!
The fare would be € 4.40 each way.
Agree. Potsdam is easy with regional trains or the S-Bahn. Once in the city, follow the signs to the castles (or take a bus from the station). I you are not afraid of walking a few km, it is so easy and a great experience any tour bus will not delver.