The ExploratoriumIt was one of the first modern science museums and it's still one of the best, with lots of simple, hands-on exhibits to go around, simple enough that they don't break.
Pros and ConsThe Exploratorium is fun for all ages, even the kids who just play with the exhibits and don't learn about the science behind them. It's a good option for a rainy day, but on a nice one, it's indoors - and you may have something similar near your home.
More About the ExploratoriumIf you need more information, check the Complete Guide to The Exploratorium. It will tell you about hours, how to get tickets, admission discounts, how to get there and the best time to go.
See where it is on a map. It's the bright yellow marker.