On July 9, 1958, a Museum of Revolution History was established in the Ninth Fort in conformity to the Decree of the Soviet Ministers’ Council. In less than a year, on May 30, 1959, the museum was opened: the first exposition about Nazi crimes in Lithuania was presented to society in four former cells of the Fort. In 1960, research started in the field of mass massacre by the Ninth Fort in order to identify the boundaries of mass murder territory and to collect proof (i.e. exhibits) about the mass murder which took place here.
In the 1960s, the memorial complex establishment of Kaunas Ninth Fort started. Four competitions of project suggestions took place in 1966-1970. In the final stage, the project by Alfonsas Vincentas Ambraziūnas, Gediminas Baravykas, and Vytautas Vielius won. After thirteen years of construction, a 32-meter monument composed of three groups of sculptures was built in the place of mass murder to commemorate Nazi victims. Near the Ninth Fort, a new museum building, having original forms, was constructed (now – the Exposition of Occupations) and a park with paths for walking was established. On June 15, 1984, the memorial complex of the Ninth Fort Museum was presented to society. It has become one of the largest memorial places in all Europe.
Since the reestablishment of Lithuania’s independence in 1990, a possibility to express ideas freely has risen, and the topics prohibited during the 50 years of Soviet occupation have been discussed. A possibility arose to speak not only about Nazi, but also about Soviet crimes, commemorating the prison which operated in the Fort in 1940-1941. New expositions were established, which introduce the visitors to all historical periods of the Ninth Fort history.