It's not rare to see a wine's country of origin listed as "California." A country into itself in the wine world, California makes enough varieties and styles to match many European wine countries. It produces a diverse range of wines that span the quality spectrum.
The most famous of the California wine regions is Napa Valley, and these wines are certainly outstanding – but it's not as broad and diverse as its larger neighbor, Sonoma County. Down south, Santa Barbara's Santa Maria Valley is well-known for its Rhône blends, as well as cool-climate varieties like Pinot and Chardonnay. The Central Coast, the largest California AVA, has many different microclimates that lead to a wide range of wines with many sub-AVAs.