The outbreak of World War II - To face the threat of invasion Switzerland increased defence spending, extended the training of recruits and built defence works.

In March 1939 reserves were called up to guard the border with Germany. The population were told to stockpile food and given instructions about how to prepare their houses in case of air raids. Also, the "Anbauschlacht" was instituted, with every available piece of land being turned into farmland (mainly for the cultivation of potatoes) in order to ensure food supplies.

Henri Guisan was appointed Commander-in-Chief of the Swiss Army with the rank of general – a rank which exists in Switzerland only at times of war.

Plans were made for a "redoubt" in the Alps, from which resistance would be organised should there be an invasion. It was hoped that even if most of Switzerland came under Nazi occupation, the redoubt would remain impregnable. The threat was omnipresent throughout the war. Germany had annexed Austria in 1938. The fall of France to the Germans in June 1940 meant that for most of the war Switzerland was completely surrounded by Germany and its allies. More details: https://www.myswitzerland.com/en-ch/world-war-ii.html





The artillery fortress Sasso da Pigna was constructed between 1941 and 1945. In the autumn of 1944, all four cannons and the battle positions were ready for action. The completed fortress was handed over to the troops in December 1945. It remained in battle readiness practically unchanged until 1998. The troops accommodation provided enough space for 420 men. The military facility extends over two levels, which can be overcome by the inclined cable car “Metro del Sasso”. By 2001, the fortress was declassified by the Swiss government. In the mid-1990s, the Federal Department of Defence appointed eight of a total of 73 artillery fortresses as monuments of national interest. One of them is “Sasso da Pigna” which can be visited as a historical fortress. One gets the feeling that the troops have just left the fortress. From the troops’ accommodation, the technical installations of earlier times up to the original cannons – everything has been preserved and can now be visited.


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approx. 8000 sq m / 2.5 km of tunnels

1st. Phase: 1941 -1943 (tunnelling and installing the 10.5cm cannons

2nd. Phase: 1943 – 1945 (further tunnelling and modifications to accommodate the 15cm cannons.

until 1998, as of 2001 no longer secret

2002 -2012

2096 meters a. s. l.

2217 meters a. s. l