Built by one of the Hamptons' most respected builders and refined by an award-winning Manhattan design firm, this masterfully crafted, just-completed residence sets a new standard for Hamptons living. Set along a private access road, the property offers sweeping open-field reserve views that feel worlds away - yet convenient to farm stands, village shops, restaurants, and world-class beaches. Spanning nearly 10,000 square feet across three impeccably finished levels served by a private elevator, the estate offers eight bedrooms, ten full baths, and two half baths - striking an ideal balance between grand-scale entertaining and intimate serenity. A dramatic double-height foyer floods the entrance with natural light, while exquisite millwork and graceful architectural detail set a warm, welcoming tone throughout. The living room features oak ceiling beams and a finely finished double-sided fireplace that opens to an inviting den. Glass doors line the rear of the home, where the beautifully landscaped grounds give way to sweeping views of the broad, open fields of the reserve beyond. At the heart of the home, the custom kitchen is anchored by a spacious center island, hand-selected natural stone countertops, a Wolf range, integrated Sub-Zero refrigeration, a glass wine column, beverage drawers, and a handsome butler's pantry. Guests may dine formally in the oak-paneled dining room, enjoy casual meals in the sunlit breakfast room, or gather beneath one of several covered outdoor areas. The generously scaled junior primary suite with a soaking tub and double vanities is a true secondary retreat. Thoughtful service spaces - including a secure package room, laundry room, half bath, and full cabana bath - complete the main level. The second-floor primary suite serves as a resplendent sanctuary crowned by a soaring cathedral ceiling and anchored by a breathtaking picture window looking out to the natural world beyond. A gas fireplace framed by a striking marble surround, dual walk-in closets, and a luxuriously finished bath with radiant-heated floors, a freestanding soaking tub, elegantly detailed vanities, and a glass-enclosed rainfall shower complete this singular haven. Four additional guest bedrooms each offer beautifully finished ensuite baths, volume ceilings, walk-in closets, and laundry access. A gracious upper-level terrace with its own fireplace overlooks the property and 18 acre reserve - an ideal setting for evenings under the stars. The lower level continues the home's elevated aesthetic with eleven-foot ceilings and a world of private indulgence: a sleek wet bar, golf simulator, state-of-the-art home theater, light-filled recreation area, and glass-walled gym. The gym opens directly onto a serene wellness terrace suited for yoga or meditation, with walk-out access to the backyard. A cedar-lined sauna and a full bath featuring a steam shower complete the spa experience, while two ensuite guest bedrooms and an additional half bath round out this remarkable level. Outside, the resort-style grounds invite effortless living and celebration. A fully equipped outdoor kitchen sets the stage for picturesque al fresco dining beneath the pergola. Spend days lounging beside the 20-by-50-foot heated gunite pool and spa, enjoying the outdoor shower, or unwinding by the bluestone patio fireplace. And for the tennis enthusiast, a north/south-facing all-weather tennis court stands ready to serve. Don't miss this complete and compelling opportunity in coveted Water Mill. This exceptional estate may also be purchased together with the adjacent agricultural reserve. This listing may include images that have been digitally altered or virtually staged. Original, unedited images are available upon request.