It is widely believed that banks in Switzerland keep their hoards of gold safely in vaults in the city, but during the Second World War, the banks discovered a more efficient, secure, and spacious place for their gold: the Alps. Using built objects as evidence, this article describes how, in 1939, a military ammunition depot in the Bernese Alps was converted into a mountain vault, for the Swiss National Bank to store its domestic gold reserves. What started as an evacuation site, along the way changed purpose from protection against the enemy to catering to them. As the gold reserves of the National Bank grew, its vaults in Bern and Zurich were no longer large enough to store all the incoming precious metals. Only by its decentralization to the Alps could Switzerland keep up the gold trade with, amongst others, Nazi Germany. Based on extensive research in the Swiss National Bank's archives, the article discloses, for the first time, evidence of the wide-ranging infrastructures and bureaucracies that facilitated the storage of gold in the Alps - a history that until today has been dominated by popular myths rather than critical historical inquiry.