But leave plenty of time for the massive Oheka - the largest residential restoration in America. It has gardens by the Olmsted Brothers. Its classicism was inspired by the French chateaux of The Loire.
 

Its grandeur also served as inspiration for “Xanadu” in the classic Orson Welles film, “Citizen Kane.”  However, unlike the home of Charles Foster Kane where rosebud was finally explained, the interior style is restrained and not a monument to excess; only the exterior and gardens were used by Welles in filming.
 

If you get lost in its interior, a Marx brothers line from "Animal Crackers" which parodied Kahn as Roscoe W. Chandler comes to mind: "You go Uruguay and I'll go mine."

Financier and arts patron Mr. Kahn built the immense 1919 residence, just 31 miles west of Midtown Manhattan, as a summer home and weekend retreat for his wife, Addie and four children, when he found their previous community of Morristown, N.J. too anti-Semitic. Their weekday home was a mansion on East 91^st Street and Fifth Avenue that is now the Convent of the Sacred Heart School.
 

After four years of construction, the Kahns would go on to entertain luminaries of the day including Chaplin, Caruso and heads of state within its walls.
 

Well, Mr. Kahn would - his wife ended up finding the partying a bit wearying after too many pretty starlets caught her husband's eye. The man who could not fit in to his previous community was now a quintessential host and touted as the “King of New York” by Will Rogers.

Oheka is now 80 percent restored after years of vandalism, including many fires, and open for visitors, including corporate retreats, weddings, fund-raisers and film production. It is 115,000 square feet with 115 rooms and 50 baths. Its survival owes to the steel and concrete Kahn insisted on using after a previous residence of his was lost in a fire. Some of the walls at Oheka are three-and-a-half feet thick. As Kahn wanted the site to have a commanding view and presence, earth was hauled by laborers to set it on the hill Oheka now enjoys.
 

The cost of the structure was $11 million plus $1 million for the original 443 acres in Cold Spring Harbor where it was erected. Cold Spring Country Club and its golf course now stand on some of the original acreage.
 

Developer Gary Melius of Long Island purchased Oheka (an acronym for Otto Hermann Kahn) and its remaining 23 acres for 1.5 million dollars in 1984 after the Cold Spring Hills Civic Association sought to save it. He has poured $30 million more into the estate in a restoration that employed many historians, restoration experts and Long Island Gold Coast architects. Slate from the original quarry in Vermont was brought in; workers were dispatched to the Library of Congress to unearth letters Kahn had written about the gardens to revive them.
 

“There were many naysayers who advised him (Mr. Melius) against buying Oheka, but he forged ahead despite a host of problems ranging from the terrible state of disrepair to issues with the town of Huntington zoning board,” said Mary McCaffery, a frequent visitor from Bethpage, N.Y.