Warsaw, Krakow, Lodz, Poznan, Gdansk, Wroclaw
Warsaw and Lodz
Warszawa [Warsaw, current capital] and Kraków [Cracow, previous capital].
The biggest cities are Warsaw, the capital and Lodz. However Katowice and its surrounding area are bigger and the cities of Poznan, Wroclaw and Krakow are also very important.
Are you thinking that someone is going to list all the cities in the country of Poland? Check link for a reference to Poland.
a lot of cities like about 15
There are two places with main seaports in Poland: the first one is Tricity with: - Port of Gdansk - Port of Gdynia the second one is North-Western Coast with: - Port of Szczecin-Swinoujscie. It's difficult to say which one is the most important. They are more or less equal, yet specialising in different tasks.
Well there are cities all over Poland, but if you mean the most populous cities, then they are actually pretty spread out; the top three most populous cities all throughout Central/Southern Poland.
Poland
People in Poland live on the country side and the cities/towns.
Poland
Warszawa (Warsaw), Kraków (Cracow), Gdańsk, Gdynia, Sopot, Poznań, Łódź, Wrocław, Białystok, Kielce, Katowice, Lublin, Rzeszów.
Poland's Shipbuilding Industry.