I found myself at Castello di Amorosa a few years ago when it first opened with my local Napa friend. It was such a revelation actually- built to look like a castle with an underground dungeon of sorts a.k.a. the wine tasting room. So I always bring my out-of-towners whenever they want:

1. a photogenic view - great for photoshoots. Don't forget to make a trip at the top of the castle
2. wines that are sweet - most of Castello's wines are on the sweet, fruity side
3. wines that are difficult to find - some wines are only sold at the winery
4. kid-friendly - their non-alcoholic Grape Juice Riesling is a must try. Drinking Mott's will never be the same again. 
4. did I say photoshoot? seems like you went on a trip to Europe instead of Napa!

wine tasting

castle

the little one trespassing, um, checking out the dining room