Television personality and heart surgeon Dr. Oz and his wife are evidently behind the purchase of Louwana, a landmarked house built in 1919 that changed hands last week via an $18 million deed, according to records filed with the Palm Beach County Clerk’s Office.

A three-year $5 million mortgage on the beachfront house bears the signatures of Mehmet C. Oz, better known simply as Dr. Oz, and his wife, author and television host Lisa Oz, courthouse records show.

The 12-bedroom, 12,483-square-foot house has four fireplaces, a guest house, a cabana, a tennis court, a three-car garage and extensive gardens, according to its sales listings. There are also original Mizner details including a "Scheherazade" stairway, cypress ceilings and original blue octagonal tile floors and walls in the upstairs master bathroom. Louwana sits on a 1.2-acre lot with 150 feet of oceanfront, a little more than a half-mile south of the Palm Beach Country Club.

The house has a more informal floor plan, with almost all of the rooms capturing ocean views.

Dr. Oz has been a longtime visitor to Palm Beach, where his wife's family has vacationed for decades, according to a story published several years ago in Palm Beach Life. Property records show Lisa Oz's parents, Dr. Gerald and Emily Jane Lemole, own two houses on the island.

“Louwana is in a great location. It’s a charming, beautiful house,” said Cristina Condon, a Sotheby’s International Realty agent who said a confidentiality agreement prevented her from discussing the sale, the seller or the buyer.

Condon initially listed the house in early 2008 at $30 million. In 2013 the property was priced at $22 million. The house had been under contract since last year, said Condon. She didn’t provide a reason for the prolonged closing process.

“Every notable visitor or resident of Palm Beach either stayed or was entertained there over the years,” said historian Augustus Mayhew.

The town granted the house landmark status in 1980.