If you’ve ever wondered how cable cars work, the nifty (and free) Cable Car Museum explains and demonstrates it all. Far more than a museum, it’s the living powerhouse, repair shop, and storage place of the cable car system and is in full operation, complete with exposed machinery that pulls the cables under San Francisco’s streets. You and your kids will become mesmerized by the massive groaning and vibrating winches as they thread the cable that hauls the cars through a huge figure-eight and back into the system using slack-absorbing tension wheels. Afterward, head over to the Musee Mecanique, a spectacular (and also free) penny arcade museum housing one of the largest privately owned collections of antique coin-operated mechanical musical instruments in the world —160 machines dating back from the 1880s through the present (and they still work!). Show the kids how their pre-Wii parents used to entertain themselves with Grand-Ma Fortune Teller and Laughing “Fat Lady” Sal.