Hear that whirring beneath the cable-car tracks? That's the sound of the cables that pull the cars, and they all connect inside the city's long-functioning cable-car barn. Grips, engines, braking mechanisms…if these warm your gearhead heart, you'll be besotted by the Cable Car Museum. See three original 1870s cable cars and watch cables whir over massive bull wheels – as awesome a feat of physics now as when Andrew Hallidie invented it in 1873.