Westerplatte Westerplatte is a peninsula in Gdańsk , Poland , located on the Baltic Sea coast mouth of the Dead Vistula ( one of the Vistula delta estuaries ) , in the Gdańsk harbour channel . From 1926 to 1939 it was the location of a Polish Military Transit Depot ( WST ) , sanctioned within the territory of the Free City of Danzig ( now Gdańsk ) . It is famous for the Battle of Westerplatte , which was the first clash between Polish and German forces during the Invasion of Poland and thus the first battle of the European theater of World War II . History . Resort . The resort was established on the Westerplatte peninsula around 1830 which had a beach , a forested park , an ocean - side bath complex and health spa facilities . The transit depot . In 1925 the Council of the League of Nations allowed Poland to keep 88 soldiers on Westerplatte , which the Poles had secretly increased to 176 men and six officers by September 1939 . They were armed with one 75 mm gun , two 37 mm Bofors antitank guns , four mortars and a number of medium machine gun s . There were no real fortifications , only several concrete guardhouse s hidden in the peninsula ' s forest . The Polish garrison was separated from Free City of Danzig ( Gdańsk ) by the harbor channel , with only a narrow isthmus connecting the area to the mainland . In case of war , the defenders were supposed to withstand a sustained attack for 12 hours after which a relief from the main units of the Polish Army were to arrive . The Polish garrison ' s commanding officer was Major Henryk Sucharski , the executive officer was Captain Franciszek Dąbrowski . Battle of Westerplatte . On September 1 , 1939 , only minutes after the German Luftwaffe ( Airforce ) had begun the invasion of Poland by dropping bombs in a series of raids on the city of Wieluń by Junkers Ju 87 Stuka s , at 04 : 45 local time , the battleship " Schleswig - Holstein " , then on a " courtesy visit " to the Free City of Danzig , opened fire on the Polish garrison without warning . This was followed by an attack by Lt . Willhem Henningsen ’ s storm unit from the Schleswig - Holstein and the " Wehrmacht pioneers . " However , soon after crossing the artillery - breached brick wall , the attackers were ambushed by the Polish defenders , with small arms , mortar and machine gun fire from concealed and well - positioned firing points that caught them in a crossfire . Another two assaults that day were repelled as well , with the Germans suffering unexpectedly high losses . Over the coming days , the Germans repeatedly bombarded Westerplatte with naval artillery and heavy field artillery along with dive - bombing raids by Junkers Ju 87 Stuka s . Repeated attacks by 3500 German soldiers were repelled by the 180 Polish soldiers for seven days . Major Henryk Sucharski had been informed that no help from the Polish Army would come . Cut off , with no reinforcements or chance of resupply , he continued his defense , keeping the main German force stalled at Westerplatte and so preventing further attacks along the Polish coast . On September 7 the Major decided to surrender , due to lack of ammunition and supplies . As a sign of honor for the soldiers of Westerplatte , German commander , Gen . Eberhardt , allowed Major Sucharski to keep his sword while being taken prisoner . Post - war . The ruins of the defenders ' barracks and guardhouses are still there . After the war , one of the guardhouses ( # 1 ) was converted into a museum . Two 280mm shells from the " Schleswig - Holstein " prop up its entrance . A Monument of the Coast Defenders ( " Pomnik Obrońców Wybrzeża " ) was unveiled in 1966 .