Work/vacation Poland (Warsaw)

Hi
I´m going for work to Poland 3 days in Warsaw ( Protected content ) then to Krakaw ( Protected content ) for 4 days, after that I have 3 extra days ( Protected content ) , I have seen a lot of great things about Wroclaw can you make any suggestions on where to go what to see, what other sights to see?
Any suggestions for Warsaw, and Krakow are welcome
Thanks