Is Terezin worth the trip- I know the story and am very interested in the Holocaust, but not sure if going to see it is worth giving up a day in the city?

The answer may denpend on, how many days you have in Prague.

I thought it was certainly worth it. But, as kappa1 said... how many days do you have in Prague?

we have 3 days- tomorrow is our last day- did the jewish quarter, the castle, old town and new town and now have one day left

No, I'd stay in Prague with such little time remaining. Bummer!

Recommend the stunning Loretto church, the Strahov monestary and it's libary. The monestary also has a couple of brewerys there. Also, Petrin Hill (the little Eiffel Tower) and the museum in its basement (which I totally forgot about when I visited it!)

Enjoy your last day!

Oops.... in case the spelling police catch me:

libary = library
its = it's