It has 15 wineries in one cool building! Tastings are roughly $15 for 3-4 tastes.
This is a lovely little zoo where Casey and I live, admissions is $10-15/person.
Point Reyes is a very popular hiking spot. Roughly 2 hours away.
Fentons is famous for its ice cream! There are also lots of shops around the area.
If you'd like to sample the sparkling wine Napa has to offer, give them a try! Tasting start at $28 for 3 oz. pours of three wines.
This is a pretty cool place to see and get local olive oils, meats, cheeses, etc. Rather on the expensive side, but still cool to visit (and taste).
This is an up and coming brewery in Fairfield (where Casey grew up). Fun atmosphere and they just added food and expanded!
This is a tasting room that has taken residence in an old admirals mansion on Mare Island. Really cool place and a surprisingly deserted island. Ask Hillary and Stephen for suggestions (Casey's sister and brother-in-law).