Parliament House (Budynek Sejmu). The parliament of Poland has an upper house, the Senate, and a lower house, the Sejm. Both houses are accommodated by the Sejm complex in Warsaw. The parliament itself is without an official name; the Constitution of Poland refers only to the Sejm and the Senate.
It’ s free of charge and you can meet some Polish politicians or watch a debate if you are lucky, It is best to book 3 month in advance online.