My absolute favorite stop in California is Bodie State Historical Park. Bodie is a modern ghost town that has been left exactly the way it was. The funeral parlor still has coffins on display, the school house has books on the teacher’s desks, etc… It is as though time froze. The amazing thing about Bodie is that as you walk the streets you feel like the past inhabitants are walking beside you.
More information can be found at: http://www.parks.ca.gov/?page_id=509