Luxury upper-level duplex residence on a quiet one-way street in the heart of Washington Square, offering approximately 3,500 sq. ft. of thoughtfully designed living space. This elegant home features 5 bedrooms, 4 full bathrooms, and an open floor plan ideal for both everyday living and entertaining. The sun-filled living and dining area showcases a marble fireplace and opens to a spacious private deck with sweeping Boston skyline views. The chef's kitchen is equipped with premium appliances, including a Wolf range, a breakfast bar, and abundant workspace. The spacious primary suite features a private balcony, marble bath with an oversized Jacuzzi tub, radiant heated floors, and custom closets. A second ensuite bedroom also offers a private balcony, while additional bedrooms provide flexibility for guests, a home office, or family living. Additional highlights include four private outdoor decks and balconies, hardwood floors, central air, laundry on the 2nd floor, custom built-ins and closets, a built-in surround sound system, Nest thermostats, abundant natural light, and two outdoor parking spaces. An elevator provides convenient access from the parking area to the main entrance. Ideally located just moments from Washington Square's restaurants, cafs, shops, the MBTA Green Line (C Branch), and the Driscoll School, this exceptional residence offers a rare combination of luxury, space, and convenience in one of Brookline's most desirable neighborhoods.