The largest New World wine region in the world, California is home to more than 4,200 wineries and is the world's 4th largest wine producer. Spanish missionaries in the 1700s introduced the states's first vineyards, but the Gold Rush of the 1850s brought a population boom, many from European nations, who brought with them vines and a wine-consuming culture. More than a century later, California's best-known sub-region is Napa Valley, home to some of the world's finest expression of Cabernet Sauvignon and Bordeaux blends. Twenty miles to the west in a cooler coastal zone, the Sonoma Valley is home to remarkable Chardonnay, Pinot Noir and Zinfandel wines. In the Central Coast, the Paso Robles AVA is home to the state's most vaunted Rhône varietals, with a smattering of world class Cabernet Sauvignon. Fifty miles due south from there, Santa Barbara County's unique transverse mountains make it an ideal location for Pinot Noir and Chardonnay production that rivals those of Sonoma County.