On the north-east Poland is the land full of lakes, forests, rivers and meadows. this place is called "Mazury". I was there once on canoeing camp. It was amazing, completely different than theese industrial view. Also we have access to the Baltic Sea on North. Lots of wild beaches, rocky cliffs and also forests. And the last places full of nature in Poland are mountain ranges, mainly in southern Poland. Mountains like Sudety or Karpaty are most popular.
Uh, i've never thought that I love so many places in Poland ;)