I routinely take classes to the San Francisco Fed. Great learning experience. They have so much cash in their vault, I can’t tell you. It’s stacked five or six tiers high, several hundred feet long and at least 100 feet wide. It’s a warehouse of cold hard cash! There’s tens of billions of dollars there and they take you right to it! Also, you will get a feel for the organization in a way that you can’t get any other way.  Put on your to do list. It’s really interesting.