In the historic heart of Sag Harbor-a village defined by its whaling heritage and contemporary cultural gravity-Residence A emerges as a singular architectural achievement. Occupying a commanding 250'+/- of prime water frontage, this estate is not merely a residence; it is a four-level masterwork of light, glass, and stone, curated for the global citizen who demands total discretion alongside unrivaled nautical access. This unparalleled pedigree is a collaborative triumph between the visionary J. Bialsky of Bialsky Premiere Design & Development and the world-renowned Hollander Design Landscape Architects, the property represents a seamless dialogue between the built environment and the Peconic Bay. Every line is intentional, every view is framed, and every material is selected for its ability to withstand the coastal elements while maintaining a refined aesthetic. Spanning a staggering 16,974 SF+/- of total living space, the residence is designed as a vertical sanctuary, where grand-scale entertaining meets quiet, private retreat. The interior volume boasts 12,551 SF+/- of meticulously crafted interiors featuring a palette of organic textures and state-of-the-art finishes. The layout accommodates 8 palatial bedrooms and 10 bespoke bathrooms, ensuring ample space for family, guests, and live-in staff. An outdoor al fresco experience of tiered terraces and lounge decks provide a multi-sensory connection to the water. With a rooftop sanctuary, a crowning achievement, featuring a private pool and spa suspended above the harbor, offering a 360-degree vantage point of Sag Harbor's gold-coast sunsets. For the yachting enthusiast, the property offers a level of utility rarely found in private residential real estate. Exclusive marina access: The estate includes a private, deep-water marina featuring two 60' boat slips. Located at the epicenter of the Hamptons' maritime scene, providing immediate access to the open Atlantic or the sheltered coves of the Shelter Island Sound. Beyond the views, the residence functions with the precision of a high-tech fortress. From the secure private garage parking-a rare luxury in the village-to the integrated smart-home systems that manage climate, lighting, and security from anywhere in the world, This residence is the ultimate turn-key asset for the high-net-worth portfolio.