Gundlach Bundschu Winery is California's oldest continuously family-owned winery, and is the third oldest winery after Buena Vista Winery (established a year earlier by Agoston Haraszthy). It is still owned and operated by the founder's heirs and today led by the sixth generation, Jeff Bundschu. The winery's 320-acre (1.3 km2) estate vineyard, named Rhinefarm by Bavarian-born Jacob Gundlach in 1858, is located within the Sonoma Valley AVA of Sonoma County, at the crossroads of the Sonoma Valley, Los Carneros AVA and Napa Valley AVA, along the Mayacamas Mountains. They specialize in estate-driven, sustainably farmed Bordeaux reds and cool climate varietal wines.