As I studied in Poznan and I still have many close friends living there, I just can not imagine visit to Poland without stopping in Poznan. Personally, I think that it is one of the most beautiful cities in Poland with a wonderful pub-scene. I can not remember when I had had so much time at the pub, as I had in Poznan's "Zak" where I went with Artur, one of my classmates from the university. People are so nice, friendly and interactive at Polish pubs, that I would not be surprised if you would make a life-long friend during a single night's visit to a typical Polish pub.
Old Market Square in Poznan is absolutely beautiful, both during the night:
...and during the day:
Poznan University of Economics:
The Imperial Castle:
1st of May decor at Pub "Zak":
At Zak, there were many interesting types of people. One of my favorites was this girl with a very original bang: