Most things in Napa Valley are very expensive, but here's a fantastic free art exhibit. Driving through the valley last week, I noticed a sign that said wine tasting and free photo exhibit. Given that we had a little time, I pulled in, half expecting to see some so so photos of the valley. Not so, instead there were magnificent art photos from some of the most famous photographers - Karsh, Atget, Adams, etc. I found out that what is on display changes and is one a part of the owner's collection.
Also, from time to time they have wine tasting and art evenings, but unfortunately we were only there for the day. Can't speak to the wine, as I wasn't drinking that day, but if you are into high quality photography, this is definitely a (short) stop worth taking.