The next morning, we head inland and north to the Napa Valley. More than 280 wineries are now squeezed into this 35-mile-long valley, which sits between the Vaca and Mayacamas Mountains.

For a relatively small region, the Napa Valley's influence in matters of culinary taste is enormous. One place to introduce yourself to the culture of food and wine is Copia center, which offers demonstrations, tastings, and other programs. You can eat very well at Copia, but the valley's other food offerings are so tantalizing that you'll want to save room for meals at other places: New stars include Cindy's Backstreet Kitchen in St. Helena and Père Jeanty in Yountville.

Napa's wine scene never stands still. As we drive the Silverado Trail, we find ourselves gaping at the Darioush winery. A new facility replacing the temporary tasting room is set to open this summer, a grand, over-the-top architectural statement that seems to encapsulate Napa's rise to America's premier wine destination. Outside the tasting room, we encounter Darioush president Bernard La Borie. "At heart," he assures us, "we're a boutique winery, focused on the craftsmanship of winemaking." Still, he admits that Darioush displays some extravagant showmanship. "You can't ignore a huge, travertine-fronted building inspired by Persepolis," he says.