I strongly recomend the Domain Chandon tour and tasting. Domain Chandon is in Yountville (just north of Napa).
When you are done go next door the the Veterans Home and watch a baseball game. The Veterans Home serves those that have served our country. It is a special place not only for the history that these men represent, it is also the host to many regional baseball programs. Besides, it is the only baseball field with grape vines coming through the outfield fence.
My son has play in 2 tournaments there. It is a very powerful experience as our young men play baseball and entertain the residents (veterns) of the home. During games you will get many a vet in either wheel chairs of scooters lining the backstop. When the games are over, the kids get an opportunity to "meet" many that have so valiently served our country.
It is wonderful experience that can be both meaningful and powerful as we teach a new generation about our country's history.