There is not a more private and wonderful experience in wine tasting in the Napa Valley that I know of. Only one group at a time; you must reserve in advance. Then, you get buzzed in to the property and drive a windy road to the McCrea house. While waiting for the tasting, you can look around at the wine making equipment and perhaps some semillion grapes drying in the sun. Then, you are greeted by one of the owners (in our case, the wife), and taken into their house. You sit on a porch overlooking the Napa Valley and you get to taste the wines while learning about the process and products of this single-owner 60 year old estate.
In addition, if you like Graves-style wines, they are fantastic, long-lived, and collectible. A memorable experience.