Square feet: 20,000
Description: This Beaux Arts wedding cake of a building is a return to the Gilded Age, when millionaire's mansions lined upper Fifth Avenue. It stayed in the family of tobacco magnate James Duke for more than 100 years before being sold in 2005 for $40 million.
Back on the market since January, the home has exquisite details, including ornate moldings and woodwork, inlaid floors, paneled walls and a wrought-iron staircase with brass decorations. There are 11 fireplaces, three elevators and a roof garden.
Tall windows give it splendid views of Central Park and the Metropolitan Museum of Art.
For more information: Brown Harris Stevens
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Last updated July 16 2010: 6:14 AM ET