Though Nicholson Ranch is smaller than other Sonoma-area wineries (comprising 40 acres), it's a hit with visitors thanks to its intimate setting. Wines produced here – the majority of which are made with estate-grown grapes – include chardonnay, pinot noir, merlot and syrah. Another interesting facet of the production process: The vineyard ages its wines in French oak barrels, which are uniquely stored underground in caves. 

Recent travelers said this relatively small winery was big on charm. The intimate setting was complemented by friendly and informative guides and gorgeous views of surrounding Sonoma. Reviewers also appreciated that the bottles of wine were reasonably priced. 

Located on the county line between Napa and Sonoma, Nicholson Ranch – which is open from 10 a.m. to 6 p.m. daily – is located on Napa Road but within Sonoma County boundaries. Wine tastings start at $15 per person. Cave tours, which include wine tastings, start at $30 person. For reservations (which are required for groups of six or more and for the combined cave tour and tasting), travelers will have to call or email in advance. For more information, visit Nicholson Ranch's website.