A bit of early 20th century history: With the establishment of Poland in 1918, the mostly-German city of Danzig became an isolated “free city” surrounded and partly administrated by Poland. In the 1930s the German population here became heavily Nazified and, coordinated with the German invasion of Poland, rose up and attacked the Polish population. In the post office were about 49 civilians who improvised a defense of the building. They held out for 14 hours, eventually retreating to the basement, where gasoline was poured onto them and lit to force a surrender. The survivors were then marched through the city, where the German spat and threw rotten vegetables at them, this on the way to their execution.
This is the post office that they defended, with a monument nearby. The Germans, once in control, treated the Poles very badly. When the Russians came and Poland was reestablished as a nation, though now occupied by Russians, the Poles threw the Germans out. They only come back as tourists. The Germans never appreciated early on before and during the war what the consequences of their behavior would be should the war be lost. This building, which I think shows the Polish determination against the Germans more than anything else in the country – houses a small museum but seems to be generally unused and not very well maintained.