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518 New Castle Ave, Portsmouth
$35,000,000
6 Beds ⋅ 9 Baths ⋅ 5114173 MLS
There are properties that simply cannot be replicated. Privately sited on 7.7 waterfront acres on Portsmouth's coveted Shapleigh Island, 518 New Castle Avenue is a once-in-a-generation New England estate, an extraordinary convergence of scale, privacy, architecture, and waterfront living just moments from the heart of downtown Portsmouth. With 13,450± square feet, this magnificent Shingle Style residence was conceived on a grand scale, pairing timeless coastal architecture with exceptional craftsmanship and sophisticated modern living. Georgian-inspired millwork, stately Tuscan columns, intricate wainscoting, and beautifully proportioned interiors create a residence of remarkable presence, while walls of windows capture sweeping water views and an ever-changing maritime landscape. Across 17 rooms, the estate offers 6 bedrooms, 7 full and 2 half baths, and an impressive collection of formal and informal living spaces equally suited for everyday living and grand-scale entertaining. A newly added balcony overlooking the pool creates an elevated vantage point of the estate's sweeping water views. Beyond the home, manicured grounds descend toward the Piscataqua River, where a private deep-water dock provides direct access to Portsmouth Harbor and the open Atlantic beyond. An attached 3-car garage is complemented by a separate 3-car garage with a finished 1-bedroom, 1-bath guest accommodation above, creating a private and flexible retreat for visitors. Nearly 6,000 square feet of unfinished lower-level space offers exceptional flexibility and storage, while a new roof completed in 2025 represents a significant recent improvement. Yet perhaps the estate's greatest luxury is one that cannot be recreated: complete seclusion across 7.7 waterfront acres while remaining connected to downtown Portsmouth and its cultural, culinary, and coastal lifestyle. 518 New Castle Ave is a landmark NH estate and a rare opportunity to steward one of the region's defining legacy properties.

518 New Castle Ave, Portsmouth

69 Richards Ave, Portsmouth
$2,100,000
6 Beds ⋅ 6 Baths ⋅ 5099048 MLS
Ideally located on coveted Richards Avenue within the Little Harbour School District, this exceptional residence offers a rare balance of privacy, lush outdoor spaces, and proximity to the best that Portsmouth has to offer. Downtown restaurants, boutique shopping,the waterfront, Prescott Park, and the Farmer's Market are all within easy reach, while nearby athletic fields, the Public Library, and Portsmouth Junior High add everyday convenience just a stone's throw away. Thoughtfully designed gardens create a secluded setting around the home. In the rear, an expansive terrace provides an elegant backdrop for entertaining, leisurely dinners, and evenings outdoors. Gather with family and friends to take in a spectacular view of the Portsmouth Fireworks over Leary Field from a number one vantage point! Beautifully appointed and ideally located, this distinctive property offers a private retreat with the cultural, recreational and civic amenities of Portsmouth just outside your back door.

69 Richards Ave, Portsmouth

53 Austin St, Portsmouth
$3,600,000
6 Beds ⋅ 6 Baths ⋅ 5095121 MLS
The Pickering-Heffenger House c.1804 Live where history was made and where diplomats, dignitaries, and world leaders once gathered. The Pickering-Heffenger House is one of Portsmouth's most significant residences, prominently featured in Richard Candee's Building Portsmouth and John Mead Howells' Architectural History of the Piscataqua. Its most celebrated chapter occurred in 1905 when Dr. Arthur Heffenger, a retired U.S. Navy physician, hosted members of the Russian delegation during negotiations for the historic Portsmouth Peace Treaty. The grandeur of that era remains evident throughout the home with quadruple crown moldings, marble fireplace mantels, soaring ceilings, and extraordinary millwork. Thoughtfully modernized for today's lifestyle, the residence offers a beautifully appointed granite kitchen, wide-board cherry floors, six bedrooms, and six renovated bathrooms that seamlessly blend historic character with modern comfort. The original carriage house and stable have been transformed into three residences consisting of two one-bedroom apartments and one two-bedroom apartment, creating flexibility for guests, extended family, rental income, or staff accommodations. Perhaps most compelling are the property's future possibilities. It can continue as one of Portsmouth's great private estates, become a multi-generational family compound, or be thoughtfully repositioned as a condominium conversion opportunity. An existing inn license also creates potential for boutique hospitality, subject to approvals. Situated along tree-lined Austin Street and just steps from downtown Portsmouth, this is more than a home, it's an opportunity to own, preserve, and redefine one of the Seacoast's truly iconic properties.

53 Austin St, Portsmouth

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