Julia Koch, widow of late billionaire David Koch, has sold the couple's handsome townhouse in Manhattan to an unknown buyer for $41 million. The deal was completely off-market, and the property was never listed for sale. David and Julia Koch paid $40.25 million for the property in 2018, so the deal isn't a particularly profitable one.

Located just off of Park Avenue, the home boasts a total of around 15,000 square feet of living space, with six stories, eight bedrooms, and touches like a first-floor garden, a media room, a spa, a sports court, and an open staircase that connects all six floors. At some point, the property was reportedly renovated by architect Peter Marino.

The property has an elevator for accessing all six floors. It has a total of ten bathrooms and was described in a prior listing as being a combination of "modern convenience and luxury."

(Photo by Andrew Toth/FilmMagic)

The sale is only the latest big real estate deal made by Julia Koch in recent years. She bought two Upper East Side apartments sometime last year from the estate of Paul Allen, the late co-founder of Microsoft, paying a total of $101 million for both.

In 2021, she spent $70 million on a Southampton property.

Julia is also preparing to sell her 740 Park Avenue duplex, having listed it with an asking price of $48 million. That listing, like the Manhattan townhouse sale, is being handled by Leighton Candler of the Corcoran Group, who issued a brief press statement:

"Every detail of the 76th Street townhouse was perfect, and we are now excited to focus on the sale of Mrs. Koch's recently renovated 740 Park Avenue apartment."

Koch, 61, is currently serving as president of her late husband's David H. Koch Foundation. The non-profit organization is focused on issues relating to medical research, education, arts funding, and other causes.

When her husband died in August 2019, Julia inherited his $58 billion fortune and instantly became one of the richest women in the world.

Today, Julia's $62 billion net worth makes her the 20th richest person in the world and third richest woman in the world behind only Walmart heiress Alice Walton ($67 billion) and L'Oreal heiress Francoise Bettencourt-Meyers ($90 billion).