You can mention here for example, Roztocze National Park and around the seaside.
The fact that in Poland there are many national parks are the best proof of how special this place is.
According to statistics, in 2012 Kraków was visited by 7.3 million tourists including 2.1 million foreign travelers (over 30% of their grand total).175176 The visitors spent over 2.5 billion złoty in the city (without travel costs and pre-booked accommodations).
Most foreign tourists came from Great Britain (over 25%), with German, French, Spanish, Italian and American visitors closely following.The Kraków tour-guide from the Lesser Poland Visitors Bureau indicated that not all statistics are recorded due to considerable number of those who come, staying in readily available private rooms paid by cash, especially from Eastern Europe.175 The main reasons for visiting the city are: its historical monuments, recreation as well as relatives and friends (placing third in the ranking), religion and business.There are 120 quality hotels in Kraków (usually about half full) offering 15,485 overnight accommodations.177 The average stay last for about 4 to 7 nights.
The survey conducted among the travelers showed that they enjoyed the city's friendliness most, with 90% of Polish tourists and 87% foreigners stating that they would personally recommend visiting it.175 Źródło: https://en.wikipedia.org/wiki/Krak%C3%B3w#Tourism