Kleine Berlin (little Berlin in German, actually incorrect, because Berlin is not feminine in German, it's Kleines Berlin) is the largest complex of underground anti-aircraft tunnels, dating back to the Second World War, still existing in Trieste. Given its hilly conformation, Trieste is crossed by numerous anti-aircraft tunnels, but the kleine Berlin complex is particular for its size, its extension, and for the fact that it can be visited by the public. The complex is located practically in the center of the city, at the base of the Scorcola hill, and precisely at the beginning of via Fabio Severo, opposite number 11. It is made up of two distinct but communicating sectors: the part built by the Italians (and precisely by the municipality of Trieste), and used as an air-raid shelter for the civilian population; the part built by the German military, with a completely different structure, used as a deposit, warehouse and anti-aircraft shelter. The works began in the years before the Second World War and then continued in the following years until the end of the war.