Set on 2.1 acres abutting the protected Long Pond Greenbelt, this 4,195-square-foot modern estate offers a rare blend of architectural sophistication and natural serenity, just minutes from Sag Harbor Village. With 4 bedrooms and 4.5 bathrooms, the home is anchored by a dramatic double-height great room, where walls of floor-to-ceiling glass frame the surrounding landscape and a Belgian wood-burning fireplace serves as both a striking focal point and an efficient whole-home heat source. Designed for seamless living and entertaining, the main level flows effortlessly from the great room into a professional-grade kitchen featuring an oversized waterfall island, and into a dedicated dining area that opens directly to the outdoors. Thoughtful amenities enhance the experience, including an en-suite guest bedroom, private home theater, and a fully equipped gym. Upstairs, the layout is intentionally divided into two wings for optimal privacy. The primary suite occupies its own side, complete with a walk-in closet, spa-inspired bath, and private terrace overlooking the grounds. Opposite, two additional en-suite bedrooms provide comfortable accommodations for family or guests. The outdoor setting evokes a private resort, centered around a heated gunite pool with integrated spa and waterfall. A well-appointed pool house includes a kitchenette, infrared sauna, and outdoor shower, while the landscaped grounds feature an irrigated garden, fire pit, and expansive bluestone patios. A detached garage completes the property. Beyond its design and amenities, the home is built for lasting performance, with a four-zone HVAC system with ionic air scrubbers, a triple-stage water filtration system, and a full-property generator. A truly turnkey offering in one of Sag Harbor's most naturally preserved settings.