My husband is a coin collector, and has visited the Mint in San Franscisco, so this was on our Must Do List, as well. It's close to the Old City, so if you aren't too tired, The Mint is a short walk away. It's a free, self-guided tour about 45-60 minutes, and you can't take pictures. You can watch them make coins, and there are lots of coins/medals on display. My husband was impressed with the classic comemmerative coins near the end of the tour. It was nice tour and we would go again.