Just some musings from a former tour guide from around the bay.
Napa gained its popularity from a famous 1976 blind tasting, known as the Judgement of Paris. As two wineries from Napa took the prestige of best red and best white wine. From that point on, Napa's spot on the map was solidified. Food followed. Napa also has some very unique geological rarities which add to it's landscape and activities.