If you don't know, San Francisco started sourdough bread. Boudin is San Francisco's oldest operating business and has been making this type of bread since the 1800s. Today they own and operate several bakeries around the San Francisco area. Grab breakfast, lunch or a snack at the most convenient location when in town. I highly recommend the location in Fisherman's Wharf. They not only offer tours, but you can watch the bread being made just from a window if you prefer not taking the tour. Plus, they make some crazy things out of their bread like teddy bears!