Located on an idyllic tree lined block off of Park Avenue, this classically detailed 10 into 9 room duplex apartment features 4 bedrooms and 4  bathrooms perfect for entertaining and everyday living.  Luxurious prewar features throughout include 9 ft beamed ceilings, handcrafted moldings, and gracious dimensions, while additional updated features including a dedicated proper laundry room make this the perfect Upper East Side home.  Enter through the elegant foyer and step into the formal living room with 4 tree top windows providing a serene exposure which provides ample light throughout the day.  Opposite the living room are a large formal dining room and kitchen, which could readily be combined to create a large open style eating and living space.  The main floor offers a commodious master suite with cavernous walk-in closet, beyond which is an updated master bathroom.  The luxurious powder room completes the main floor.  Down the staircase are an additional 3 bedrooms, each with en-suite bath, and a den that provides the perfect space to watch a film, read a book or catch up on paperwork.  This level also includes an abundance of storage and a landing with separate entrance to the lower floor.  124 East 84th Street is a lovely, well-serviced boutique cooperative building.  Doorman from 8:00am to 12:00 midnight.  Live-in super.  Storage units, bike room and laundry room in basement.  The 4,5, and 6 trains are just two blocks away, and the schools, shopping, dining, museums and other conveniences of the Upper East Side are literally right outside the front door.  3% flip tax.