Switzerland Turned an Alpine Ammunition Depot Into a Secret WWII Gold Vault, Study Finds

As Europe edged toward World War II in 1939, Switzerland faced a dilemma that went beyond defending its borders: it needed to safeguard one of its most strategic assets, its gold reserves. New historical research shows the Swiss National Bank responded by moving large quantities of gold into fortified Alpine infrastructure, converting a military ammunition depot carved into the Bernese Alps into a highly secured underground vault.

The findings, published in the Journal of Contemporary History, draw on previously undocumented details from the Swiss National Bank’s own archives. According to historian Ludo Groen of ETH Zurich, the transformation began in 1939 when the ammunition depot was adapted to house the bank’s domestic gold reserves, offering a level of protection and secrecy that urban vaults in Zurich and Bern could not match.

The mountain vault was initially intended as an emergency evacuation site should Switzerland be attacked. But as the war progressed and the country’s gold bar holdings expanded rapidly, the Alpine facility was turned into a permanent storage centre for reserves that no longer fit in the city vaults.

The research challenges the long-held belief that Swiss gold was stored primarily beneath major banking centres. Archival evidence instead shows that growing wartime inflows of precious metals demanded an entirely new storage infrastructure — one that included security, transport routes and administrative systems built around the mountain vaults.

The Alps had long been central to Switzerland’s national defence strategy through its ‘National Redoubt’ concept, and the study shows financial security became intertwined with that defensive landscape. The decentralised Alpine storage let Switzerland keep managing its bullion while adapting to a rapidly shifting geopolitical situation, offering historians new insight into how the country protected its reserves while maintaining neutrality through one of the most turbulent periods in modern history.