What are the cleanest/ most naturally diverse/ beautiful/ cities in California?

Especially cities which are appropriate for outdoor activies- surfing/ climbing/ rafting/ hiking...

Public Comments

1. For natural diversity, cleanliness, lack of pollution and the outdoor activities you mentioned (with the exception of rafting), I'd either Santa Barbara or San Luis Obisbo. For rafting, I'd say Ashland, Oregon (okay, it's not technically California, but it's right on the border, it's beautiful, it's clean and has the amazing Rogue River).
2. San Diego!