Have a work event in Warsaw and Krakow. What should I see while I'm there?

Basically I'm flying in and out of Warsaw in November, with time in Krakow in between.

I have a couple of extra days on either end of the trip. What else should I do?

Should I take more time to explore Warsaw and Krakow? Or should I visit another city like Wroclaw, Poznan, Lodz, etc?