First thanks for the awesome invaluable advice provided thus far. So here is my final question.
Does this itinerary (days per) seem right.
Arrive Berlin July 23 mid day, depart Tuesday by train early morning. So 3 full days and 1/2 day. Travel by morning train to Prague on Tuesday. Depart Prague on Friday mid day. So that is 2 1/2 days (not really counting Friday morning which is fairly wasted but there is only one flight out per day to Milan on Easy Jet). I have been told that Berlin is simply amazing and bursting with history. So I have tried to give us enough time to really take in the major museums, tours and just walking around time. Are we short-changing Prague or is this itinerary pretty good? Also, I had wanted to go to Terezin outside of Prague but feel our schedule is probably too tight for that. Should I consider reducing Berlin by one day in order to fit in Terezin? I have a teenage son who just studied the Holocaust and he asked to visit a concentration camp. So I would hate to by-pass an important learning moment. I know there is a concentration camp to visit outside of Berlin but have not researched that as thoroughly as Terezin. Thank-you for your excellent feedback! BTF
Near to Berlin is Sachsenhausen Concentration Camp and also Ravensbruck Concentration Camp for Women. They are an easy train ride away, and if you go with one of the tour companies in Berlin, you will also get a lot of history to go along with this visit. I believe the price from most of the tour companies run about 15 euro for an adult and less for students.
There are also 3rd Reich tours which are an excellent way of learning about the history of Berlin in the war, or you could do a Cold War tour as well as just one of the regular walking tours that will give you a fantastic orientation of the city. This allows you to go back later to whatever interests you.
Terezin was not a typical concentration camp. It was a showcase for Red Cross. If you decide to see it I explained how to get there on the way to Prague in my earlier reply.
I think it's the right balance. Berlin is a much bigger city with more museums and activities. You can get a good sense of Prague with 2 1/2 days.