Although most of Diamond Mountain (as well as its peak) are located in Sonoma County, the reputation for great wine making has long associated it with the Napa Valley side. It’s the warmest viticultural region in the Mayacamas Mountains. There are less than 500 acres of vines planted on Diamond Mountain which is the smallest acreage under vine in Napa Valley. Following this trend is Reverie Winery, which is one of the smallest wineries in Napa Valley. In a unique valley, shared with two other wineries: Diamond Creek and Von Strasser, lies Reverie Winery. The winery itself is inside a re-creation of a 125 year old barn located on the property.