Presenting a rare and compelling joint offering at 55 & 70 Peconic Avenue-a modern compound opportunity in one of Shelter Island's most coveted waterfront enclaves. Together, these two distinct yet complementary properties deliver scale, privacy, and irreplaceable southwest-facing water views across the Peconic toward Southampton-creating a legacy estate unlike anything else on the market. 55 Peconic Avenue, newly completed in 2022, is a bold contemporary residence set on 1.4 acres, designed for seamless year-round living. Southwest water views flood the open-concept main level, where living and dining spaces center around a striking raised propane fireplace and flow effortlessly into a sleek, island-driven kitchen built for gathering. The private primary wing features a walk-in dressing room and spa-caliber bath with outdoor shower access, while two guest bedrooms occupy the opposite wing for ideal separation. A partially finished lower level offers flexible bonus space with full bath and storage. Outdoors, a 20' x 40' Gunite pool with integrated spa, marble accents, and custom tile anchors resort-level living, complemented by an entertaining area, lush irrigation, and a detached three-car garage. 70 Peconic Avenue is a commanding, four-level waterfront estate with nearly every room oriented toward panoramic water views. From the dramatic entry foyer to the east-facing living room with oversized windows and classic fireplace, the home pulls the Peconic directly indoors. The chef's kitchen-appointed with Wolf, Sub-Zero, and Bosch appliances-centers around a marble island and opens to a dining space framed by water and warmed by a propane fireplace. Coffered ceilings elevate the architectural detail throughout. The primary suite offers a Rumsford fireplace, spa bath, and private waterfront deck, while additional en-suite guest rooms ensure comfort and privacy. The third-level lounge with wet bar and retractable-awnings deck delivers breathtaking elevated views. A fully finished lower level adds substantial living space for media, guests, or extended stays. The waterfront infrastructure is exceptional: approximately 105 feet of PVC bulkhead, staircase to a sandy beach, and a 75-foot L-shaped dock with extension and swimming ladder-offering direct boating access and effortless shoreline living. Offered together, 55 and 70 Peconic Avenue create a one-of-a-kind Shelter Island compound-pairing modern poolside luxury with commanding dock-front waterfront living. Turn-key. Irreplaceable. A generational opportunity.