How it is made - US Dollar (Inside The US Federal Reserve and Official US Mint)

The United States Bullion Depository, often known as Fort Knox, is a fortified vault building located within the United States Army post of Fort Knox, Kentucky. The vault is used to store a large portion of United States official gold reserves and occasionally other precious items belonging or entrusted to the federal government. It is estimated to hold roughly 2.3% of all the gold ever refined throughout human history.