The Bay Area Discovery Museum (557 McReynolds Rd., Sausalito, 415/339-3900, www.baykidsmuseum.org [1], Tues.–Fri. 9 a.m.–4 p.m., Sat.–Sun. 10 a.m.–5 p.m., $10 adults, $8 children) offers kids of all ages a chance to explore the world they live in.
The focus definitely rests on the younger set here; most of the permanent exhibits are geared toward small children, with lots of interactive components and places to play. Kids can check out easy-to-understand displays that describe the natural world, plus lots of Bay Area–specific exhibits. The Discovery Museum also boasts a theater and a café.
Links:
[1] http://www.baykidsmuseum.org