San Francisco is a great city. There are tons of things to see and do. We have (maybe) pretty much done it all on our various trips throughout the years. Our favorites places for the boys are the Exploratorium and California Academy of Science. We also love the zoo, the museums and the beaches. If you're looking to escape the crowds at some of the big venues, try visiting these places: Cable Car Museum and Musée Mécanique.
These big wheels are what are turning the cable cars, impressive and loud:
This museum near Fisherman's Wharf is fun to walk around:
With old game machines:
The Cable Car Museum is fun to see and look at the machines and old photos of the city while the games museum is fun for pushing buttons. Great for kids and parents alike!