Extra
No it's not.
It is worthy though if you do with the tour. If you think that for 35 bucks you will get to know about the story of the Castle and the wine industry in Napa, it is cheap.
Extra $$ to taste. Go into town and get a wine tasting passport at the tourism office. After a few wineries you've made your money back. (I think that is where it was at.)
If you pay for any of the guided tours, the tasting is included as part of the experience.
No, you have pay for it.
As part of 35$ admission.
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