Also known as Kaunas IX Fort and Devintas Fortas.

Devintas Fortas is part of a Stronghold in the northwest section of Kaunas (Kauno). At the end of 19 century, under the Russian Empire direction, Kaunas created a defense system in which the town was surrounded by a series of forts and batteries (groups of men, large guns and equipment.

Construction of 9th Fort began in 1902, and it was completed on the eve of the First World War.

From 1924 this Fort was Kaunas' prison branch, house of corrections, with 100 hectares of auxiliary farm land which contained an orchard planted by prisoners.

During the first Soviet occupation years (1940–1941) 9th Fort became a prison of the NKVD, from which political prisoners were sent to Soviet camps.

Upon area occupation by the National Socialist German Workers' Party in 1941, it became an area of mass murder.

On October 4, 1941 a large selection of Jews from the small ghetto were marched and executed in the Devintas Fortas. On October 29, 1941, the Great Action took place and another 9,200 Jews were murdered.

Four trains from Germany were diverted there in 1941 and on November 25 and 29, 4,934 Jews were executed upon arrival.

French train convoy No 73, which departed from Drancy May 15, 1944 on its way to Tallinn, Estonia, stopped in Kaunas. Approximately 600 men were removed and brought to Fort 9 or sent to Provieniskies to work in the peat bogs. Those who remained at the fort were almost immediately executed.

About 50,000 people were executed there, including between 18,500 - 30,000 victims of the Holocaust. Currently, it houses a museum and memorial devoted to the victims of wartime mass executions and is the most complete example of a Russian Empire fortress.

In 1943 the Germans operated special Jewish squads to open the mass graves and burn the corpses.

After WWII it again came under Soviet occupation and was used as a prison between 1944 – 1948.

In 1958, the Devintas Fortas was dedicated as a museum. During 1959, its first exhibition was opened, memorializing the crimes that had taken place there. The museum later expanded its scope to cover the fortress' entire history.

It also has exhibitions on the Soviet occupation after WWII and actions that lead up to the freedom of Lithuania from Soviet occupation.