Hi Ania Marysia. That is a very good question. There are many cities worth visiting in Poland. The most popular are: - Warsaw - the capital of Poland, with the Wilanów Palace, Łazienki Park, Palace of Culture and Science, Belweder, - Krakow - the former capital of Poland, with the Cloth Hall, the Main Square, the large city park - Błonia, Wawel Castle with the cave of the Wawel Dragon, - Gdansk - city by the sea, with a long coastline along the Motlawa River, Crane Gate, Main Town Hall, Neptune's Fountain, - Zakopane - is called the capital of the Polish mountains, with Krupówki, Kasprowy Wierch peak, Giewont, Gubałówka, which can be reached by cable car, Wielka Krokiew ski jump, - Toruń - Nicolaus Copernicus was born in this city, here you can find the most delicious gingerbread in the world, many monuments, museums and an amazing planetarium. I hope I managed to answer your question. Or maybe you need more information about other Polish cities?