A truly extraordinary estate set on over 20 acres, featuring an impressive stone manor, a remarkable circa-1817 historic guest house, and a substantial detached garage and event building. Beautifully landscaped grounds, a picturesque front pond and fountain, and exceptional outdoor spaces create a private setting for gracious living, entertaining, and an equestrian-inspired lifestyle. The stone manor offers gracious, light-filled living spaces and exceptional architectural detail. The residence features formal living and dining rooms, an elegant library with custom built-ins, a sophisticated gourmet kitchen with a large island and abundant cabinetry, and a welcoming morning room overlooking the grounds. The main-level owner's suite offers a private sitting area, dual baths, and walk-in closets. Multiple fireplaces, custom millwork, and thoughtfully designed spaces provide an exceptional setting for both everyday living and entertaining. The upper level provides three additional bedrooms and a comfortable salon/seating area, while the lower level offers a wellness area, guest accommodations and generous storage. A dedicated pet-washing and grooming room within the main residence features a built-in bathing tub and is separate from the laundry room. The remarkable circa-1817 guest house adds a rare layer of history and versatility to the estate. Currently configured as two independent apartments, it offers four bedrooms, original wood floors and wood-burning fireplaces, dual kitchens, separate well and septic systems, and a generator—an exceptional opportunity for guest accommodations, extended family or other flexible uses. The substantial detached barn-style building has been transformed into a versatile garage and event space, offering tremendous flexibility for entertaining, gatherings, vehicles, hobbies, equipment and storage. For the equestrian enthusiast, the property retains a meaningful connection to its horse-country heritage, with a large fenced sand arena and enclosed round pen. The expansive grounds offer an exceptional foundation for those who envision further developing or enhancing an equestrian lifestyle, subject to applicable requirements. Outdoor living is equally impressive, with mature trees, gardens, terraces, lawns, the scenic pond, and numerous spaces for relaxing and entertaining. The property consists of three tax IDs/parcels totaling over 20 acres. Boundary changes are planned for fall 2027, including Kingsview Middle and Poolesville High School. Buyers should verify assignments with MCPS. A rare opportunity to own a distinctive Montgomery County estate combining a magnificent stone residence, historic guest house, extraordinary entertaining spaces, equestrian appeal, and beautifully curated grounds.