One of Wine Country's big mysteries has been solved, though it did not remain a secret for very long.

The hilltop Napa Valley estate owned by the late wine giant Robert Mondavi, listed for sale at $25 million last year, was sold this fall for an undisclosed sum to an unnamed buyer.

But word inevitably leaked out. The buyers: wine power couple Gina Gallo and her husband, Jean-Charles Boisset, according to Wine Spectator magazine.

Boisset declined to comment Thursday, saying it was a private, family purchase. Gallo could not be reached for comment.

The sprawling home, which spans 11,500 square feet, was designed for Robert and Margrit Mondavi by architect Cliff May, who also designed the Mondavi winery and was credited with developing the California Ranch-style house. Its tall windows and open interior design — it only has two bedrooms — allow 360-degree views of the Napa Valley. A 50-foot swimming pool is located in the home's living room under a retractable roof.

"When Mr. Mondavi built it, it was a unique design built for his lifestyle," said John J. Cuticelli Jr., CEO of New York-based Sheldon Good & Co., which brokered the deal in an auction.

The Silverado Trail property was originally posted for $25 million when the Mondavi family placed it on the market in May 2010, but the price was later reduced, according to reports. Cuticelli said his company took six weeks to sell the property through its auction process.

"It had a minimum bid of $13.9 million, and certainly the price was something that the Mondavi family was willing to accept," Cuticelli said.

Mondavi, who died in 2008 at the age of 94, is credited with bringing worldwide attention to the Napa Valley through his innovations in the wine industry, such as using French oak aging barrels and stainless steel fermentation tanks. His winery was sold to Constellation Brands in 2004 for about $1 billion.

Now, two very influential names in the California wine industry have acquired a home built for a wine industry legend.

Gallo, granddaughter of E&J Gallo founder Julio Gallo, is a winemaker who has served as the face of the company's Sonoma County wine operations.

Boisset is president of Boisset Family Estates, which owns several California wineries and has roots in Burgundy, where it is among France's largest wine companies.

The couple was married in 2009 and Gallo gave birth to twin daughters in May.

They will have neighbors with some familiar names: Mondavi's sons, Tim and Michael, both live nearby, according to Wine Spectator.

Among the property's 56 acres are two that are suitable for growing grapes in Napa County's Stags Leap AVA. Whether Gallo or Boisset will utilize the grapevines to create a new estate wine or another tradition remains to be seen.

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