Perfectly positioned on the 18th floor of 520 Park Avenue, this magnificent full-floor simplex residence redefines modern classical luxury. Impeccably designed with custom fixtures and finishes, every detail in this turn-key home was considered. Spanning 4,613 square feet, the home is introduced by a private, key-locked elevator landing that opens into a grand entrance gallery, setting the tone for the elegant, light-filled interiors beyond. The expansive south-facing entertaining rooms - including the living room, formal dining room, and eat-in kitchen - span the full width of the building, each bathed in natural sunlight and showcasing city views through oversized windows. Designed with both scale and sophistication, the residence offers four bedrooms, five full bathrooms, and one powder room. Notable features include 11-foot ceilings, solid oak flooring in classic herringbone and overlay patterns, corner bay windows in the living room and primary suite, and multi-zone climate control ensuring year-round comfort in every room. The windowed eat-in kitchen, designed by Robert A.M. Stern and crafted by Christopher Peacock, is a showcase of timeless craftsmanship and modern functionality. It is outfitted with top-of-the-line appliances including a Sub-Zero refrigerator with dual freezer drawers, six-burner Wolf range with vented hood, two Miele dishwashers, speed and convection ovens, warming drawer, wine refrigerator, and dual sinks. Two large pantry closets provide additional storage. The kitchen flows effortlessly into the formal dining room and onward to the corner living room - creating a seamless space for grand entertaining or intimate gatherings. The primary bedroom suite offers a serene retreat, with abundant custom closets and two luxurious en suite bathrooms featuring radiant-heated marble floors, polished nickel fixtures, and custom Robert A.M. Stern vanities. Each secondary bedroom is equally well-appointed, featuring custom millwork and en suite marble baths with radiant heat. A fourth bedroom or library, located just off the living room, offers flexibility and includes its own en suite bath and generous closet. The laundry area, with side-by-side Electrolux washer and vented dryer, is conveniently positioned in the bedroom hallway. Developed by Zeckendorf Development, creators of 15 Central Park West, and designed by Robert A.M. Stern Architects, 520 Park Avenue stands as a modern classic in limestone - a soaring yet discreet tower rising nearly 800 feet, composed of just thirty-five full-floor simplex and duplex residences. Residents enjoy truly white-glove service and an unparalleled suite of amenities, including a 24-hour doorman and concierge, double-height indoor swimming pool, fully equipped fitness center and pilates studio, resident lounge and screening room, and a graciously landscaped garden salon. 520 Park Avenue offers a rare blend of tranquility and convenience - at the crossroads of the Upper East Side Historic District and the prestigious Plaza District, moments from Central Park, Fifth Avenue shopping, and Manhattans finest dining and cultural institutions. This turn-key home can be sold furnished or unfurnished. Private storage is included in this sale.