Wroclaw in the winter was beautiful.  The river adjacent to the Ostrow Tumski (Cathedral Island) was partly frozen and filled with swans.  I love visiting small cities because usually you don’t have all the hype of a major touristy city.  You feel like you are the only tourist there and the locals really appreciate you visiting.  Being the fourth largest city in Poland and one of the oldest, it goes to say that there are plenty of old buildings worth visiting, one of them being the Cathedral.  Make sure you stop at the main market square (Rynek) in the heart of Wrolcaw where you can appreciate 12th century Gothic architecture as well as brightly colored facades.