Set within a meticulously restored Stanford White mansion on Lower Park Avenue, this exceptional duplex penthouse offers approximately 3,000 sq. ft. of refined interior living space along with two private setback terraces. Perfect for entertaining, the 3-bedroom, 3-bath residence combines modern sophistication with classic charm. The lower level showcases 6 towering floor-to-ceiling windows and a stunning Poggenpohl kitchen, equipped with Absolute granite countertops, stainless steel cabinetry, a Sub-zero refrigerator/freezer and wine cooler, a Wolfe 5-burner gas range, Miele convection oven and warming drawer, and a Miele dishwasher. Diagonally laid white bleached oak floors flow throughout, while both the living and dining rooms are warmed by wood-burning fireplaces. This floor also features a guest bedroom, a Carrera marble bathroom with a glass-enclosed shower, and a laundry area complete with a washer/dryer. Ascending the architectural staircase leads to the second level, where 5 skylights illuminate the den, which features French doors that open onto a terrace. The primary bedroom suite boasts a solarium with an entire wall of windows, offering an abundance of natural light, and an adjoining spa-like bathroom. The third bedroom also includes an en-suite bath. A spiral staircase provides access to a tranquil rooftop deck. Recently upgraded 4 zone central air conditioning and a Sonos sound system, installed throughout the home and on both terraces, add to the modern conveniences of this luxurious property. Constructed in 1890 and designed by McKim, Mead & White, 23 Park Avenue stands as a rare example of a late 19th-century private mansion. This 5-story Italian Renaissance palazzo is pet-friendly, equipped with an elevator, and benefits from a live-in superintendent available from 7 AM to 4 PM. Located at the crossroads of NoMad and the Murray Hill Historic District, the co-op is moments from transportation hubs, the Morgan Library & Museum, Whole Foods, Trader Joe's, Fairway, and a variety of renowned restaurants in the vibrant NoMad area.