SHOWINGS BY APPOINTMENT ONLY. A rare offering on one of the Upper East Side's most storied blocks, this exceptional 2,715 square foot duplex is set within a 25-foot-wide limestone mansion in the heart of the Gold Coast at 35 East 68th Street. Here, timeless architecture and modern luxury come together in a way that feels both grand and deeply livable. A keyed elevator opens directly into a striking mahogany-paneled foyer, setting the tone for what unfolds. The south-facing living room is expansive and filled with natural light, framed by nearly floor-to-ceiling windows with Juliet balconies. A marble wood-burning fireplace anchors the space, while a beautifully integrated bar with a Sub-Zero wine cooler and refrigerated drawers makes it ideal for entertaining. Just beyond, a windowed media alcove with custom built-ins creates a more intimate retreat, thoughtfully separating the bedroom wing on this level. The primary suite is a true sanctuary, complete with its own wood-burning fireplace and an extraordinary custom walk-in closet by Ornare. The closet flows seamlessly into a five-piece marble bath featuring a Jacuzzi soaking tub, radiant heated floors, dual sinks, and a mirrored television integrated into the vanity. A second bedroom, accessed through elegant mahogany bookcase doors, offers its own en-suite bath with a deep soaking tub. A sculptural mahogany staircase leads to the upper level, where a light-filled formal dining room with a limestone wood-burning fireplace becomes the centerpiece for gatherings. This floor is as functional as it is beautiful, with a full bathroom, home office, laundry room, and a spacious third bedroom with custom millwork. The chef's kitchen is both refined and highly equipped, with custom cabinetry, stone countertops, radiant heated floors, and a full suite of appliances by Sub-Zero, Miele, Gaggenau, and Thermador, including a six-burner cooktop, grill, double ovens, and warming drawer. Throughout the residence, rich mahogany millwork, coffered ceilings, and elegant crown moldings speak to the home's heritage, while central air and a Crestron system provide seamless modern control. The Dunham House is an intimate, eight-residence cooperative built in 1899 by Carrère & Hastings, the celebrated architects behind landmarks such as The Frick Collection and New York Public Library Main Branch. Positioned between Park and Madison Avenues, and just moments from Central Park, this address places you at the epicenter of classic Upper East Side living, surrounded by world-renowned museums, Madison Avenue boutiques, and some of the city's finest dining. With a setting that embodies the elegance of prewar New York at its peak, this is more than a residence. It is a piece of the neighborhood's history, reimagined for modern life.