In the days after Hitler invaded Poland in September 1939, Hitler traveled with his special train America to Poland to follow the war on site so to speak, and to make short visits to the front. The train thus served as a headquarters during the Polish campaign. Between September 19 and 26, Hitler and his closest associates stayed at the luxurious Grand hotel in the resort town of Sopot north of Gdansk. From here he twice travelled to the front at Warsaw to follow the fighting closer, but still at a safe distance.
Current status: Preserved (2023).
Location: 54°26' 50.64" N 18°34' 05.95" E
Get there: Walk from central Sopot.
Follow up in books: Seidler, Franz W. & Zeigert, Dieter: Hitler’s secret headquarters (2004).
The hotel survived the war only with minor damages. The hotel retained its status as a luxury hotel during the communist era and several famous personalities stayed at the hotel. However, over the years the hotel had to be modernised, but this only happened after the fall of communism. Nowadays the hotel is called Sofitel Grand Sopot, but is still a luxurious hotel right at the shores of Baltic Sea.