Fort Knox has been the site of the United States Bullion Depository since 1937, and it contains approximately 3 percent of all the gold that has ever been refined. At various times, the depository has held other valuable items, but gold remains its main holding.
As of 2014, the fortified vault at Fort Knox contains the world's second-largest stockpile of gold bullion. Its stock of 4,578 metric tons of gold is second only to the 7,000 metric tons held by the Federal Reserve Bank of New York. Visits to Fort Knox from the members of the general public are not permitted.