The Risiera di San Sabba was a Nazi concentration camp, located in the city of Trieste, used as a police detention camp (Polizeihaftlager), as well as for the transit and elimination of a large number of prisoners, mainly political or Jewish prisoners. In addition to the prisoners destined to be killed or deported, several civilians captured in roundups or destined for forced labor were also imprisoned there. The victims (estimated between three thousand and five thousand, on the basis of the testimonies collected) were shot, killed with a blow to the back of the head, hanged or poisoned with the exhaust fumes of vans specially equipped for this purpose. Because of these killings, the Risiera di San Sabba is sometimes referred to as a "extermination camp", even if this definition (in German Vernichtungslager) is reserved by international historiography to a series of structures - almost exclusively located in Poland - whose main or exclusive activity was that of the physical elimination of the deportees. In the concentration camp there was a crematorium, of rudimentary conception, purposely built in place of the rice dryer, which was used to burn the corpses. Today the Risiera has become a museum. In 1965 it was declared a national monument.