Prominently sited in prestigious Observatory Circle, the historic Heurich-Parks House at 3400 Massachusetts Avenue, NW presents a rare opportunity to own a fully reconstructed Washington estate. Originally built in 1925 by architect Albert S.J. Atkinson and once home to Christian Heurich Jr., a philanthropic businessman, as well as Marshall Parks, known as the "Father of Pediatric Ophthalmology". This distinguished Spanish Mission-style residence was masterfully reconstructed and expanded in 2017 by renowned BarnesVanze Architects, seamlessly blending historic provenance with modern luxury. Set on a beautifully landscaped and level 0.39-acre lot with irrigation, the property is introduced by a grand circular driveway and features a detached 2-car garage with guest house studio above and additional parking pad. Encompassing approximately 13,900 square feet, the residence offers 7 bedrooms, 9 full baths, 2 half baths, and an elevator. The main level is defined by elegant entertaining spaces, complemented by a stunning open kitchen with marble countertops, herringbone floors, and a sunlit breakfast room. Designed for both grand-scale living and everyday comfort, the home includes an extraordinary indoor swimming pool with pool bath, bar, and Desert Air dehumidification system. A convenient main level bedroom suite also completes this level. The luxurious owner's suite features a spa-inspired bath and dual walk-in closets. There are four other bedroom suites on this level. The expansive lower level offers a recreation room, exercise room, wine storage, laundry, full bath with sauna, and multiple storage rooms. A truly exceptional offering combining architectural significance, modern amenities, and premier location adjacent to the Naval Observatory and Vice President's Mansion!