It takes a pretty great museum to revive a nap deprived three year old late in the afternoon after a day full of enough sites and sounds to fill a week in normal life mode. The Exploratorium is that kind of museum. Hands-on doesn't begin to describe the extent to which children and adults alike can immerse themselves in science. Some of the exhibits were so simple yet so absorbing. Like this beach ball/safety cone/air blower contraption. The museum was absolutely a highpoint on our San Francisco trip chock full of high points.