Perched atop one of Back Bay’s most iconic addresses, this extraordinary ~6,000 SF penthouse duplex redefines luxury living with grand entertaining spaces, intimate retreats, and breathtaking panoramic views. A private elevator opens into a stunning formal foyer, setting the stage for the dramatic living room, where soaring ceilings, intricate moldings, a fireplace, and floor-to-ceiling windows frame sweeping vistas of the Charles River and Cambridge skyline. A richly paneled study with a fireplace and wet bar adds warmth and sophistication, while the elegant dining room offers a front-row seat to dazzling city views, seamlessly connecting to a spacious eat-in kitchen. The upper level boasts 6+ bedrooms, 6 full baths, a laundry room, and abundant storage, ensuring ultimate comfort and privacy. This professionally managed, owner-occupied concierge co-op includes private storage, 1 dedicated parking space, and an additional guest spot as available. A true 1 of a kind Back Bay residence!