When my parents were recently visiting from Australia we spent quite a lot of time playing tourist in San Francisco. On more than one occasion we found ourselves walking past the Wells Fargo Museum on Montgomery Street and we were all keen to go in and check it out. However we kept walking past at times when it was closed!
On the last full day that my parents were with us we found the time to fit in a visit to the Wells Fargo History Museum (during opening hours even!) and we were not disappointed. There are lots of fun, hands on exhibits relating to the history of banking and San Francisco, and, best of all, entry is free.