A Magnificent Blend of Victorian Grandeur and Modern Luxury on the Charles River. This exceptional 2,600 sq ft full-floor residence is a rare offering in one of Bostons most storied brownstones, designed by renowned architects Peabody & Stearns in the 1870s for developer Henry Bigelow Williams. Unit 4 preserves the elegance of the Gilded Age while delivering a private, modern sanctuary at the heart of the Back Bay. Accessed by a private elevator, the home opens to a marble foyer and expansive living space with soaring ceilings, original crown moldings, hand-carved fireplace mantels, and rich hardwood floors. Four hidden doors, including one that secures the primary suite as a discreet safe room, add mystery and utility. Four walk-in closets provide unparalleled storage. The newly renovated chefs kitchen is anchored by a statement La Cornue French range and refined Italian porcelain countertops. Custom cabinetry and a large center island create both elegance and efficiency. Two-bedroom suites offer spa-level comfort; the primary includes a double shower, and vanity wrapped in marble. At the rear, catch sunsets on the TV lounge framed by arched windows leads seamlessly to a private terrace overlooking the Charles River-a true rarity in the city. Ideal for entertaining or private relaxation, it offers a front-row seat to seasonal views and river life. Additional features include central air, smart-home controls, in-unit laundry, and deeded parking. Moments from the Esplanade, Newbury Street, and Copley Square, this residence delivers refined living in Bostons most iconic neighborhood.