Duplex apartment in Park Avenue tower that once housed John D. Rockefeller,

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The apartment “was designed to feel like a house within an apartment building,” Crocker told Mansion Global. “It has the private elevator vestibule, which goes to each floor if it’s needed, and entertaining spaces [on the main level] with sleeping spaces upstairs.”

Each of the unit’s four bedrooms features an en suite bathroom, Crocker said, while a primary suite boasts its own terrace. In addition to multiple living and entertaining spaces with large windows and fireplaces, the main level includes a wood-paneled library with a built-in bar, listing photos show. The two floors are connected by a dramatic spiral staircase, which retains its original banister.

“With so many [historic] properties they get so changed over the years,” Crocker said. “This apartment has been renovated, of course, but a lot of the layout is in line with the original floor plan.”

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A swinging door leads from the formal dining room into the spacious, renovated kitchen which includes a butler’s pantry and a separate wine refrigerator, according to Crocker. From this part of the home, a staircase leads up into an area that was originally used as staff quarters, and currently houses laundry, a bathroom and an “office that could be a staff room,” Crocker said.

The sellers, who could not be identified, purchased the property in 2012. The previous sale price could not be determined.

The building itself has been the subject of media coverage over the decades, including the 2005 book “740 Park: The Story of…