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Courtesy of Janet Sylvester of Great Island Realty LLC: .

350 Portsmouth Avenue

New Castle, NH 03854
  • $3,950,000
  • STATUS: Active
  • ON SITE: 49 Days
  • MLS #: 5107161
UPDATED: 48 min ago
$3,950,000
  • 3
    BEDS
  • 0.25
    ACRES
  • 3
    BATHS
  • 1
    1/2 BATHS
  • 3,238
    SQFT
  • $1,220
    $/SQFT
Type:
Single-Family Home
Built:
1977
County:
Area:

School Information

Elementary School:
Middle School:
High School:
School District:

Description

Welcome to 350 Portsmouth Avenue, an exceptional waterfront residence offering a front row seat to one of the most captivating maritime settings on the New Hampshire Seacoast. With expansive water views of the Piscataqua River and Back Channel, this remarkable property captures everything that makes New Castle waterfront living so special. From magnificent ships and iconic Portsmouth tugboats to sailboats, fishing vessels and pleasure craft, the ever changing boat traffic provides a spectacular backdrop from morning until night. A private deep water dock makes this a dream for boating enthusiasts, offering direct access to Portsmouth Harbor, the Piscataqua River and the open Atlantic. Adding to the property's unique appeal is deeded access to the Back Channel, creating a wonderful launching point for kayaks and paddleboards. Designed to embrace this extraordinary setting, the home features multiple waterfront decks for entertaining, outdoor dining or simply watching the river come alive. A walk-out lower level extends the living space outdoors, while the hot tub and sauna create a private waterfront retreat to enjoy throughout the seasons. Enjoy all the amenities that make New Castle one of the Seacoast's most coveted communities, the nearby yacht clubs, Wentworth Marina, Wentworth by the Sea Country Club, Great Island Common, beaches and the historic charm of island living, all just minutes from downtown Portsmouth. And with New Castle's exceptionally low property taxes, this is a rare opportunity to combine an extraordinary waterfront lifestyle with one of New Hampshire's most desirable communities. Deep water boating out your front door. Kayaking and paddleboarding from your deeded Back Channel access. Incredible water views, spectacular boat traffic, waterfront decks, hot tub and sauna, all in the heart of New Castle. 350 Portsmouth Avenue isn't simply a waterfront home, it's a lifestyle defined by the water.

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© Copyright 2026 PrimeMLS. All rights reserved. This information is deemed reliable, but not guaranteed. The data relating to real estate displayed on this Site comes in part from the IDX Program of PrimeMLS. The information being provided is for consumers’ personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Data last updated 2026-10-17T08:06:11.823.
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350 Portsmouth Avenue New Castle, NH 03854

  • Price: $3,950,000
  • Status: Active
  • On Site: 49 Days
  • Updated: 48 min ago
  • MLS #: 5107161
3
Beds
3
Baths
1
½ Baths
0.25
Acres
3,238
SQFT
$1,220
$/SQFT
1977
Built
County:
Rockingham
Area:
New Castle
Elementary School:
Maude H. Trefethen School
Middle School:
Rye Junior High School
High School:
Portsmouth High School
School District:
New Castle
Property Description
Welcome to 350 Portsmouth Avenue, an exceptional waterfront residence offering a front row seat to one of the most captivating maritime settings on the New Hampshire Seacoast. With expansive water views of the Piscataqua River and Back Channel, this remarkable property captures everything that makes New Castle waterfront living so special. From magnificent ships and iconic Portsmouth tugboats to sailboats, fishing vessels and pleasure craft, the ever changing boat traffic provides a spectacular backdrop from morning until night. A private deep water dock makes this a dream for boating enthusiasts, offering direct access to Portsmouth Harbor, the Piscataqua River and the open Atlantic. Adding to the property's unique appeal is deeded access to the Back Channel, creating a wonderful launching point for kayaks and paddleboards. Designed to embrace this extraordinary setting, the home features multiple waterfront decks for entertaining, outdoor dining or simply watching the river come alive. A walk-out lower level extends the living space outdoors, while the hot tub and sauna create a private waterfront retreat to enjoy throughout the seasons. Enjoy all the amenities that make New Castle one of the Seacoast's most coveted communities, the nearby yacht clubs, Wentworth Marina, Wentworth by the Sea Country Club, Great Island Common, beaches and the historic charm of island living, all just minutes from downtown Portsmouth. And with New Castle's exceptionally low property taxes, this is a rare opportunity to combine an extraordinary waterfront lifestyle with one of New Hampshire's most desirable communities. Deep water boating out your front door. Kayaking and paddleboarding from your deeded Back Channel access. Incredible water views, spectacular boat traffic, waterfront decks, hot tub and sauna, all in the heart of New Castle. 350 Portsmouth Avenue isn't simply a waterfront home, it's a lifestyle defined by the water.
Exterior Features

Architectural Style Contemporary Color Gray Construction Materials Wood FrameWood Siding Driveway Paved Exterior Features Boat MooringBoat Slip/DockHot TubPrivate DockSauna Has Garage Yes Lot Features LandscapedNear Country ClubNear Golf CourseNear ShoppingNear School(s) Lot Number 10 Parking Auto OpenDirect EntryDrivewayAttached Road Frontage Yes Road Frontage Length 100 Roof Asphalt Shingle Water Access Details Deep Water AccessDock Access Water Body Access YN Yes Water Body Type River Water Frontage Length 100 Water View YN Yes Waterfront Property Yes Waterfront Property Rights Exclusively Owned

Interior Features

Appliances Electric CooktopDishwasherDouble OvenWall OvenRefrigerator Basement Access Type Walkout Basement Description Climate ControlledDaylightFullPartially FinishedInterior StairsWalkout Cooling Central AC Flooring CarpetTile Foundation Poured Concrete Has Basement Yes Heating OilForced Air Interior Features Cathedral CeilingCeiling FanDining AreaWood Fireplace1 FireplaceKitchen IslandPrimary BR w/ BANatural Light Quarter Baths 0 Rooms Total 7 Sq Ft Approx Fin Above Grade 2375 Sq Ft Approx Fin Below Grade 863

Property Features

Assessment Amount 2900900 Assessment Year 2025 Block 0 Construction Status Existing Covenants No Electric 200+ Amp Service Electric Company Eversource Flood Zone Land Only Fuel Company Nobel Fuel Pre Construction No Property Type Single Family Road Frontage Type PavedPublic Maintained Road Seasonal No Sewer Public Special Listing Conditions None Surveyed Unknown Tax Gross Amount 15636 Tax Year 2025 Taxes Tbd No Timeshare Fractional Own No Utilities Cable Water Restrictions No Water Source Public Zoning RD RE

Courtesy of Janet Sylvester of Great Island Realty LLC: .


© Copyright 2026 PrimeMLS. All rights reserved. This information is deemed reliable, but not guaranteed. The data relating to real estate displayed on this Site comes in part from the IDX Program of PrimeMLS. The information being provided is for consumers’ personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Data last updated 2026-10-17T08:06:11.823.
 
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