The Museum of the 20th century and the Shoah lets visitors experience WWII and the Shoah during the battle of Cassino. Eight rooms, through an evocative interactive and immersive itinerary, recount the early 20th century, fascism, emigration, the internment of foreign Jews, the stages towards Auschwitz, the aid to former allied prisoners, the referendum for the Republic, the reconstruction of Montecassino. 

San Donato Val di Comino was one of the most important free internment locations in Italy and the first one in Lazio. The first Jewish internees arrived in the summer of 1940 and established good relations with the population and the authorities, from whom they were welcomed and helped, and were immediately integrated. Among the internees are: Margaret Bloch, Kafka's friend and confidante; Grete Berger, an important actress of silent cinema and German Expressionism, who starred in several film masterpieces: The Student of Prague, Metropolis, Dr Mabuse, Destiny. 

With the fall of fascism and the German militarisation of the Comino Valley, San Donato became the rear of the Cassino front and the last inhabited village before the Gustav Line. The town suffered various aerial bombardments and shelling, Allied and German, from 5 November 1943 to 5 June 1944, the last day of the war in Cassino. During those months, the inhabitants, particularly the women, rescued and helped Jewish internees, Yugoslavian internees and about a thousand Allied prisoners who had escaped from the prisons in Abruzzo and Emilia Romagna, receiving certificates of thanks from General Alexander. 

The museum displays are arranged in chronological order, marked by continuous film clips. Visitors can virtually browse through documents, war diaries and unpublished writings using touch screens. Organised activities include guided tours, workshops, teacher training, studies, research, urban trekking, excursions to World War II sites, events, and Remembrance Day events.

The museum is the result of a collaboration with the Washington Holocaust Museum that began in 2018.