The Free City of Danzig was in theory a demilitarized place between 1919 and 1939. Only the police owned firearms. However, due to the strategic location of the city, the reality was different.
Since 1933 the implantation of the Nazi party in Danzig had been increasing. Although the party could not determine the annexation of the city to the German Reich, the Nazis of Danzig did everything possible to pave the way for the invasion that occurred in September 1939.
By this time, the Polish population of the city was barely 10%. Despite this, the Polish government was determined to defend the city that it considered its own by historical rights. Due to the limitations of the Versailles treaty, the Polish authorities were only entitled to a military barracks in the port and to own a post office in present-day Gdansk.
To circumvent the limitations, Poland decided to use the post office as a way to bring soldiers and weapons into the city. The supposed postmen assigned to Danzig were actually soldiers, who acted as postmen waiting for the outbreak of the conflict. In addition, they secretly gradually created a small hidden arsenal in the post office.
During the early days of Nazi Germany's invasion of Danzig, the Polish Post Office was the only major point of resistance within the city of Danzig. Today the place is a museum that narrates what happened there and where homage is paid to the first fallen in the war for Poland.
How to get to Danzig Post Office
The old Polish Post Office in Danzig is located in the center of the city. To get there the best way is to do it by public transport. You can check the tram map at the following link.