The Seventh Fort or VII Fort is a defensive fortification built in Kaunas, Lithuania and begun in 1884 and completed around 1890. Originally conceived and built by the Russian Empire and turned over to the Lithuanian Army in 1919.

The Seventh Fort was the first concentration camp in Nazi-occupied territories after the beginning of the war with the Soviet Union. German orders to concentrate the Jews of Lithuania into a separate camp were received on 29 June 1941. The next day, the decision had been made during the meeting of the Lithuanian Provisional Government to set up a Jewish concentration camp in the Seventh Fort. It was used as holding area for Jews just a little more than a month.

Up to 5,000 victims were killed in the fort's territory from 30 June 1941 until its closure on 10 August 1941. The remaining prisoners were transferred to Kaunas Ghetto. Most of them were Jewish residents of Kaunas. The largest number of victims were killed on 4 July (463 people) and 6 July (2514 people). Murdered bodies were thrown into the hole left from the half-caponier (passageway). Later other victims had been buried there too, near the fort wall. Main perpetrators of the bloody massacre were Tautinio Darbo Apsaugos Batalionas (TDA battalion officers) , together with their subordinates. TDA were organized by the Provisional Government of Lithuania in 1941 as basis for future independent Lithuanian Army, but Nazi authorities soon reorganized the battalion into auxiliary police.

Starting September 1941, the Seventh Fort become a concentration camp for prisoners of war known as Stalag 336 or Stalag 336F. Initially, the camp housed war prisoners of the Ukrainian nationality. There is evidence that about 1,500 Ukrainian prisoners died from the cold, diseases, and malnutrition in the winter of 1941 to 1942. The exact number of war prisoners dead and buried at the Seventh Fort is unknown.