Cable Car Museum
One of the city's best free offerings, this museum is an absolute must for kids and compelling for adults too. You can even ride a cable car here—all three lines stop between Russian Hill and Nob Hill. The facility, which is inside the city's last remaining cable-car barn, takes the top off the system to show you how it all works. Eternally humming and squealing, the massive powerhouse cable wheels steal the show. You can also climb aboard a vintage car and take the grip, let the kids ring a cable-car bell, and check out vintage gear dating from 1873.