Occupying the crown of The Chatsworth, one of the Upper West Side's most distinguished landmark residences, this extraordinary duplex penthouse offers an unparalleled combination of scale, privacy, outdoor living, and breathtaking views spanning Riverside Park, the Hudson River, and the Manhattan skyline. Thoughtfully reimagined as a modern residence of exceptional quality, this expansive home seamlessly blends the grandeur of prewar architecture with bespoke contemporary design. Spanning over 6,000 square feet of interior living space and complemented by over 3,740 ft2 of private terraces, this penthouse lives with the comfort and privacy of a townhouse in the sky. The dramatic Great Room serves as the centerpiece of the home, framed by oversized windows that flood the residence with natural light while capturing breathtaking views of Riverside Park and the Hudson River. Seamlessly connected to the living and dining areas, the chef's kitchen has been meticulously crafted with custom lacquered cabinetry, polished Super White quartzite countertops and backsplashes, and a curated suite of Sub-Zero, Wolf, and Miele appliances. Adjacent to the kitchen, a spacious windowed breakfast room opens directly to the terrace, creating an effortless connection between indoor and outdoor living and providing an inviting setting for casual dining, morning coffee, or entertaining. A richly appointed library, accessed through a sophisticated wet bar, offers a private retreat ideal for a home office, media room, or guest suite. Complete with an en-suite bath and direct access to outdoor space, this versatile room can easily function as a sixth bedroom, providing exceptional flexibility for modern living. Together, these thoughtfully designed spaces create an extraordinary environment equally suited to intimate gatherings and grand-scale entertaining Two exceptional private terraces provide a rare outdoor lifestyle, seamlessly blending indoor and outdoor living while offering extraordinary settings for dining, lounging, and entertaining against the stunning backdrop of Riverside Park and the Hudson River. An outdoor kitchen, motorized pergola, and multiple seating and dining areas enhance these expansive outdoor spaces, creating an unparalleled setting for both everyday living and grand-scale entertaining. An exterior staircase leads to an additional private rooftop retreat, where spectacular, unobstructed views stretch across Riverside Park, the Hudson River, Riverside Boulevard, and the Manhattan skyline. This extraordinary rooftop sanctuary offers a breathtaking vantage point from which to enjoy sunsets, river views, and the ever-changing beauty of the city. The private bedroom level is thoughtfully separated from the entertaining spaces and anchored by a luxurious primary suite featuring multiple walk-in closets and two spa-inspired marble bathrooms clad in Bardiglio Grey, Thassos, and Arabescato stone. Four additional bedrooms, each generously proportioned and with its own en suite, are complemented by a large den that can serve as a media room, home office, or private family lounge. Throughout the residence, every detail reflects an uncompromising commitment to craftsmanship, including wide-plank white oak flooring, custom millwork, polished nickel fixtures, hand selected natural stone, and refined architectural detailing. The result is a home that feels both timeless and contemporary, honoring this landmarks historic character while delivering the highest standard of modern luxury. Residents enjoy the privacy and services of a full-service and full amenity luxury building, moments from Riverside Park, Central Park, Lincoln Center, celebrated dining destinations, and the best of Upper West Side living. This newly constructed Penthouse has never before been offered. An impeccably designed and newly constructed penthouse residence with extraordinary outdoor space, iconic river views, and the scale and presence of a private home atop one of Manhattan's most coveted addresses.