Archive
History
From the first mountain fortress in 1886 to the 2023 decision to halt bunker sales — the full story of how Switzerland built the most fortified neutral nation in history.
1886
The First Fortress
Switzerland builds its first significant defensive bunker near the Gotthard railway, marking the beginning of 140 years of underground fortification.
1939–1945
The National Redoubt
Surrounded by Axis powers, Switzerland transforms the Alps into a hidden fortress. 20,000 bunkers, anti-tank obstacles, and fortifications are built. Operation Tannenbaum — the Nazi plan to invade — is never executed.
1963
Shelters for All
At the height of the Cold War, Switzerland passes a law requiring every citizen to have access to a nuclear fallout shelter. A building programme begins that will eventually create 360,000 shelters — enough for 107% of the population.
1976
Sonnenberg Opens
The world’s largest civilian shelter opens inside Mount Sonnenberg in Lucerne, designed to protect 20,000 people beneath the A2 motorway.
1987
Operation Ant
The first and only full-scale test of the Sonnenberg bunker reveals critical failures: 350-ton doors that won’t close, no radio communication, and only a quarter of the planned setup completed in a week.
1990s–2000s
The Great Decommissioning
With the Cold War over, Switzerland begins decommissioning hundreds of military bunkers. Many are sold, converted into hotels, cheese caves, data centres, and mushroom farms. Others are opened as museums.
2023
The Sale Stops
Lieutenant General Süssli announces Switzerland will halt bunker sales and reintegrate fortifications into military infrastructure. A 220 million franc modernisation programme begins. The bunkers are needed again.
Deep Dives
