The California Science Museum is a nice place to take your kids as they get older. The have hands-on learning as well as periodic exhibitions. You can also become a member and make regular vists to save on entrance fees. The last time I was there I saw "Body Worlds", where over 200 real bodies were on display using a new scientific method od preserving bodies without the usual stinky smells. I saw sectionals of bodies, organs, muscles, blood vessels, fetus, old and young people, etc. This description just doesn't give it justice as it is overwhelming to see such precision upclose. This particular exhibition brought tons of crowds, but I thought the museum did a good job of monitoring how many people can go in at any given time. They also have a decent food court onsite. Parking costs $6-8.
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