If you are under 20 years old or with a young family thenthe boardwalk and beach at Santa Cruz would probably be alot of fun. It was fairly well maintained and had a very wide beach. I was a bit distracted by the very obviously marked disposal containers for used syringes on the streets, I would not suggest going to the water front too late at night or to early in the morning.
The “Big Trees & Pacific” train that runs up to a picnic grounds may be a nice excursion, but I did not have time to check it out.