This stunning, mint-condition terraced Penthouse Duplex is located in the most prestigious Prewar Cooperative on lower Fifth Avenue. Three apartments have been newly combined and meticulously finished by acclaimed architect Joe Serrins to achieve a masterpiece of form and function, a fully modern “townhouse in the sky.” Serrins imagined this apartment as an interior landscape, where rooms flow into one another, linked by a continuous line of oversized, floor-to-ceiling windows, expansive sunlight, and landmark building views. Pivoting and sliding panels allow the rooms to function flexibly, expanding for open-plan living, or partitioning for more intimate spaces. The over-sized staircase is wrapped in walnut panels and the custom bronze and burgundy leather handrail creates a sculptural connection between the floors. Custom features include white lacquer millwork, Tundra Grey marble slab bathrooms, state of the art mechanicals, Lutron lighting, and a Sonos sound system throughout.