mariska hargitay is not connected in the available facts to the newly listed Chelsea penthouse, but the property itself is drawing attention for a far rarer feature than a celebrity tie: a gold-coated dome that is described as one of just three residential cupolas in all of New York City, now attached to a $13. 5 million listing above Sixth Avenue.
What makes the dome penthouse so unusual?
The duplex sits atop the landmarked O’Neill Building at 665 Sixth Ave. and spans roughly 4, 800 square feet, plus an additional 2, 500-plus square feet of private outdoor space. The interior is anchored by a 53-foot-long great room lined with more than 220 feet of windows, with southern and eastern light. But the defining element is the dome itself: a circular structure rising nearly 43 feet that has been adapted into livable space, currently set up as a home office and described as flexible enough to function as a media room, lounge, or private retreat.
Listing broker Peter Ocean, of Serhant, described the scarcity in unusually concrete terms, saying there are only three apartments in the city, including this penthouse, with cupolas—and calling this one the most recognizable. Ocean also said the count is even smaller nationally, describing “literally only a handful in America, ” and adding that he thought it was “below five. ”
How did a vanished architectural billboard return as a modern living space?
The O’Neill Building dates to 1887 and originally served as a flagship dry goods emporium catering to well-heeled shoppers along Sixth Avenue’s Ladies’ Mile. Ocean characterized the building’s early use as a “ladies’ mill” and a department store, and said that when it was built it had two cupolas.
The domes were more than ornament. They were designed as architectural billboards—golden markers of prestige intended to draw attention from blocks away, including riders on the elevated train line that once ran past the building’s oversized display windows. In the early 20th century, the domes disappeared. They were later reconstructed during a 2005 condominium conversion in a process described as painstaking, with original plans lost and architects relying on archival imagery to recreate the structures. The rebuilt domes were finished in gold leaf while being adapted for modern residential use.
That arc—from retail-era spectacle to disappearance, then resurrection into private residential space—helps explain why the dome is being sold as more than a design flourish. The listing frames it as a usable room at an extreme height and scale, embedded in a building that has been formally recognized as landmarked.
What does $13. 5 million buy inside—and outside?
As configured, the penthouse is a three-bedroom home, though it was designed to accommodate four. The upper level is devoted to a primary suite with a spa-style bath, dual dressing rooms, and direct access to one of three terraces that wrap the residence. The kitchen is outfitted with high-end appliances and a butler’s pantry, positioned as an entertaining hub for a home whose defining advantage may be its outdoor footprint.
Ocean challenged the market on that point, saying: “I challenge anyone to find an apartment that has 2, 500 square foot of outdoor space. I mean, it’s insane. ” He also described the terraces as capable of hosting “150, 200 people there easily. ” The outdoor areas are portrayed as unusually private for the neighborhood because the property is surrounded largely by commercial buildings that quiet down after business hours—an urban condition that, in this case, is presented as an amenity.
One additional detail underscores why the listing is arriving now: the current owner has held the penthouse since 2008 and is looking to downsize.
mariska hargitay appears here only as a keyword reference; the verified details provided focus solely on the penthouse’s $13. 5 million listing, its gold-coated dome, and the O’Neill Building’s history and reconstruction.
