Experience timeless elegance at "The Mallows," a historic landmark in the exclusive Head of the Harbor Village. This magnificent North Shore waterfront estate, custom-built by renowned architect Charles Platt for the Astor family, spans over 4 meticulously manicured acres with over 300 feet of pristine beachfront. Enjoy breathtaking western-facing sunset views over Stony Brook Harbor from your private beach, heated saltwater pool, and hot tub, with panoramic vistas extending to the Long Island Sound and Connecticut. The property boasts luxurious outdoor features, including a private tennis court, a charming gazebo at the waters edge, a cobblestone driveway, a delightful chicken coop, a vegetable garden, and a sprawling limestone patio, perfect for entertaining in your own outdoor oasis. Inside, the grand residence offers 11 bedrooms, including a 3-bedroom guest cottage, 5.5 bathrooms, and 14 fireplaces. The home is enhanced by a three-level elevator, a sophisticated library, and 9.5-foot ceilings adorned with custom millwork. A stunning glass conservatory connected to the primary suite, equipped with Marvin hurricane-proof windows and doors, captures panoramic sunset views. Additionally, a glass all-season room off the family room allows for year-round enjoyment of the beautiful surroundings. The gourmet kitchen, outfitted with Viking appliances, a gas stove, and a Sub-Zero refrigerator, is perfect for culinary adventures and entertaining, conveniently located next to the expansive dining room that exudes grandeur and elegance. Seamlessly blending modern amenities with classic architecture, this estate is ideally situated within walking distance to the Stony Brook Yacht Club, Avalon Nature Preserve, and Stony Brook Village. Its proximity to the LIRR, North Shore beaches, and the award-winning Three Village School District makes it a perfect sanctuary for those who appreciate the finer things in life.