Santa Cruz is famous for its wooden beachside rollercoaster (1924) and associated amusement park.
Now that Berkeley has been overrun by credentialist yuppies, a substantial portion of the counterculture has moved to the cheaper rent districts of Santa Cruz. Look for Volkswagen Microbuses, most of them carrying surfers
I'm personally fond of downtown Santa Cruz because it was there that I finally realized why I didn't need to live in California (see "Moving to California"). The historic Art Deco structures were mostly destroyed by the 1989 Loma Prieta earthquake but have been substantially rebuilt.
Natural Bridges State Beach, at the end of W. Cliff Drive, atracts monarch butterflies from October through May.
Remember to stop at MISTIX and get tickets to see the elephant seals at Año Nuevo State Reserve, 20 miles up the coast.