The Copper Beech Farm in Greenwich has sold for $120 million, according to real estate agent David Ogilvy.
The waterfront mansion is 50-acre and sprawls 13,000 square feet. It has 12-bedrooms, a 75-foot pool, a grass tennis court, a stone carriage house and two islands in Long Island Sound.
The Greenwich town clerk's office says the buyer of the French Renaissance-style home is Conservation Institute, LLC.
Ogilvy says Copper Beech Farm edged out a Silicon Valley property sold last year for $117.5 million.
Built in 1896, Copper Beech Farm was once owned by Andrew Carnegie's niece Harriet Lauder Greenway.
The Associated Press contributed to this report