Island locations are architecture’s ultimate playground. With limited space and the drama of isolation, they force architects and builders to think big while working within the confines of nature. Mansions on islands are bold statements carved into unique landscapes, specifically designed for their surroundings.
Take Eagle Island, where Robert Peary’s Victorian retreat sits like a sentinel over the rugged Maine coast. Or consider the South Bass Island Lighthouse on Lake Erie, a Queen Anne-style home that mixes function with flair, complete with gingerbread trim and a storybook turret. These homes wrap their architectural styles into the folds of the land.
From shingle-clad estates tucked into wooded shorelines to Mediterranean-inspired villas framed by salt-sprayed cliffs, the mansions play with light, water, and wind in ways that mainland estates can only envy. Each structure uses the isolation of its island setting to amplify its architectural presence, creating homes that are as much landmarks as they are living spaces. The result is a fascinating mix of styles, from Gothic to Colonial Revival, all tied to their environments in ways that mainland mansions rarely achieve.
15. Eagle Island Estate – Eagle Island, Maine
Eagle Island, nestled in Maine’s Casco Bay, is a fitting legacy for its original owner, Arctic explorer Admiral Robert Peary. Purchased for $200 in 1881, the 17-acre island became Peary’s summer retreat and a showcase for his boundary-pushing spirit. By 1904, he had transformed the rugged, rocky expanse into a home that was part sanctuary, part fortress, and fully representative of his larger-than-life persona.
The Peary House, at the heart of the estate, evolved over time. Initially a modest structure with a grand living room and three bedrooms, it expanded in 1906 to include a kitchen and dining wing. By 1913, Peary had added porches and even a pair of circular stone bastions — part retaining wall, part artifact display case — to protect the house from the ferocious storms that can batter the island.
Peary’s wife Josephine and daughters left their mark too, planting gardens on the rocky terrain with a mix of native and unusual species. After the family’s stewardship, the state of Maine took over in 1967, preserving it as a State Historic Site.
14. Wrentham House – Newport, Aquidneck Island, Rhode Island
Indian Spring, perched atop a rocky outcrop in Newport, Rhode Island, stands as a testament to the collaborative genius of architect Richard Morris Hunt and landscape architect Frederick Law Olmsted. Designed between 1887 and 1892, this granite-and-brownstone Romanesque mansion merges architectural gravitas with a landscape that feels effortlessly natural. Originally commissioned by William Edward Dorsheimer, a Buffalo lawyer and urban planner, the project was handed to Hunt after H.H. Richardson’s death and later completed for yachtsman J.R. Busk.
The house embraces the rugged coastal setting. Its asymmetrical massing includes turreted corners, conical roofs, and a grand, ocean-facing porch framed by low towers. A broad sweep of French doors and dormers spill light into the double-height central living space, an innovative design that became a model for American vacation homes. The pale pink-grey granite façade, contrasted with dark brownstone detailing, adds a subtle sophistication.
Olmsted’s landscaping avoided Victorian over-planting, opting instead to highlight the house’s organic connection to the location. For decades, the house languished in ruin, but its meticulous restoration (2000–2007) returned it to its rightful place as one of Hunt’s crowning achievements, admired for both its architectural brilliance and seamless integration with the landscape.
13. Dungeness Ruins – Cumberland Island, Georgia
Dungeness, built in 1886 by Thomas Carnegie and his wife Lucy, was a grand expression of Queen Anne-style architecture set on Georgia’s Cumberland Island. The mansion replaced the earlier home of Revolutionary War hero Nathanael Greene, whose widow had built a modest tabby structure (consisting of lime from burned oyster shells mixed with sand, water, and ash) on the same site in the early 19th century. When the Carnegies purchased the island in the 1880s, they transformed the site into a winter retreat.
The 59-room mansion, with its turrets, sweeping verandas, and asymmetrical design, embodied the eclectic, ornate characteristics of the Queen Anne style. The interior featured soaring ceilings, intricate woodwork, and dozens of fireplaces hinted at the life of luxury within. The estate sprawled over an expansive landscape, with gardens, stables, and servants’ quarters.
The Carnegies spent their winters here, arriving by sea and remaining until spring. After Thomas’s death in 1886, Lucy managed the estate as a family hub. By the mid-20th century, however, Dungeness had been abandoned, and in 1959 a fire gutted the structure.
12. Castle Hill Inn – Newport, Aquidneck Island, Rhode Island
Castle Hill Inn and Castle Hill Lighthouse, is set on a 40-acre peninsula at the eastern gateway to Narragansett Bay. Alexander Agassiz, a Harvard oceanographer, built Castle Hill in 1875, creating a blend of private retreat, research hub, and architectural landmark. Agassiz’s mansion, believed to be designed by H.H. Richardson, features a chalet-style laboratory, inspired by his Swiss roots, complete with a windmill-powered seawater pump for marine biology studies.
The nearby Castle Hill Lighthouse, constructed in 1890, exemplifies Richardsonian Romanesque design, with its robust granite base blending seamlessly into the rocky shoreline. Originally fitted with a kerosene-powered Fresnel lens, it gained a 2,400-pound fog bell in 1896 — much to Agassiz’s chagrin, as he opposed the lighthouse’s proximity to his estate.
Agassiz’s property later transitioned into Castle Hill Inn, a luxurious retreat attracting icons like Grace Kelly and Thornton Wilder. Today, the lighthouse stands as a listed National Register landmark, while the Inn continues to offer a mix of history, architectural charm, and Newport’s coastal beauty.
11. Palacete Los Moreau, Moca, Puerto Rico
Palacete Los Moreau in Moca, Puerto Rico, is a Caribbean fantasy masquerading as a French château. Built in 1893 by Cornelia Pellot Labadié after her husband Juan’s death, the concrete mansion rose from the ashes of an older wooden plantation house. Designed by Paul Servajean, the administrator of Central Coloso, the structure flaunts a Châteauesque aesthetic, blending European style with tropical elements. Its two towers — one housing the original library — anchor a sweeping porch, perfect for surveying what was once a 1,300-acre estate of coffee, cane, and cattle.
This was a stage for Puerto Rico’s agrarian transformation and later a muse for Enrique Laguerre’s novel La Llamarada. The book immortalized the mansion as “Hacienda Palmares de la Familia Moreau,” weaving the house and its sugar-plantation milieu into Puerto Rican literary lore. After decades of decline, the Municipality of Moca restored the property in 1993, rechristening it El Palacete Los Moreau to honor Laguerre’s work.
10. Kingscote – Newport, Aquidneck Island, Rhode Island
Kingscote, built in 1839, is credited with igniting Newport’s “cottage boom,” an era that transformed the town into a showcase of picturesque summer homes. Located at the corner of Bowery Street and Bellevue Avenue, this early Gothic Revival house was designed by Richard Upjohn for George Noble Jones, a Southern plantation owner. Its irregular roofline, steep gables, and intricate wooden details typify the Gothic style, while its sand-mixed beige paint gave the wooden structure the appearance of sandstone.
When the Jones family left Newport during the Civil War, Kingscote passed to William Henry King, a merchant linked to the Old China Trade. Over the decades, the house underwent expansions and updates. Architect George Champlin Mason added a larger dining room and service wing in the 1870s, while Stanford White of McKim, Mead & White reimagined the interiors in the 1880s, adding opalescent glass bricks from Louis Comfort Tiffany and a redesigned master suite.
Compared to later Newport mansions, Kingscote is modest, but its importance lies in its role as a forerunner. It set the tone for Newport’s evolution from a quiet seaside town to a center of architectural experimentation. Today, it remains a National Historic Landmark, preserved as a glimpse into the origins of Newport’s grand “cottages.”
9. Oheka Castle – Long Island, New York
Built between 1914 and 1919 by financier Otto Hermann Kahn on the north shore of Long Island, Oheka Castle combines the first letters of the owner’s name which he also used for his yacht and Florida villa. At 109,000 square feet with 127 rooms, it remains the largest private home in New York and among the largest in the United States.
Designed by Delano and Aldrich, Oheka was constructed with steel and concrete, making it one of the first entirely fireproof residential buildings. Kahn’s determination came after a devastating fire destroyed his earlier home, Cedar Court. The estate itself sits on an artificial hill, providing views of Long Island’s Cold Spring Harbor. The grounds, by the Olmsted Brothers, feature a sunken garden in the French style, with clipped hedges, water terraces, and formal parterres. At its height, the 443-acre property boasted an 18-hole golf course, a vast greenhouse complex, orchards, tennis courts, and a private airstrip.
Following Kahn’s death in 1934, Oheka fell into disrepair, serving various roles from a military academy to a retreat for sanitation workers. Restored in the 1980s, Oheka now operates as a hotel and event venue.
8. Admiral’s House – Governor’s Island, New York
Built in Nolan Park on Governors Island, the Admiral’s House stands as a relic of American military history wrapped in evolving architectural styles. Designed in 1840 by Martin E. Thompson and completed in 1843, the original Greek Revival structure was a study in symmetry and restraint. Its classic two-story form, accented by Doric-columned porches and scalloped cornices, had the air of a genteel country villa, until successive renovations transformed it into a showpiece of eclectic charm.
In the late 19th century, the house began its stylistic evolution. A south wing appeared in 1886, and by 1893, the roof was raised to accommodate a Colonial Revival portico. By the 1930s, Charles O. Cornelius remodeled the rear, swapping the peaked roof for a flatter profile and adorning it with wrought-iron railings. Today, the building’s Doric porches, granite steps, and ironwork detailing make it a masterclass in the layered architectural history of the 19th and early 20th centuries.
Beyond its aesthetic pedigree, the house hosted military luminaries like John J. Pershing and Winfield Scott Hancock before becoming a Cold War stage. In 1988, it witnessed a pivotal summit between Ronald Reagan and Mikhail Gorbachev. The Admiral’s House was designated a New York City landmark in 1967 and added to the National Register in 1972.
7. Rosecliff – Newport, Aquidneck Island, Rhode Island
Rosecliff, a shimmering icon of Newport’s Gilded Age, takes its design cues from the Grand Trianon of Versailles but adapts the French grandeur into something distinctly American. Designed by Stanford White of McKim, Mead & White and built between 1898 and 1902 for silver heiress Theresa Fair Oelrichs, the mansion was conceived as a social hub. The white terracotta exterior and French-inspired axial gardens make a unique statement while paying homage to Baroque sensibilities.
White’s architectural ingenuity shines in Rosecliff’s spatial layout. The mansion’s “H” shape centers on the ballroom, with Corinthian pilasters, arch-headed windows, and recessed doorways creating an interplay of grandeur and balance. The heart-shaped staircase in the grand Stair Hall adds drama, while the upper-level suites feature a mix of privacy and connectivity. Below, the all-but-invisible kitchens and service areas reflect the era’s rigid social hierarchy.
6. R.J. Reynolds Mansion – Sapelo Island, Georgia
Originally constructed in 1802 by Thomas Spalding using a “tabby” mix of lime, shells, ash and water, Reynolds Mansion is located on Georgia’s secluded Sapelo Island. Designed as the centerpiece of Spalding’s plantation, the house fell into disrepair after Civil War damage before Detroit automotive engineer Howard Coffin restored it in 1912. Later, tobacco heir Richard Reynolds acquired the estate, preserving its history while repurposing it for marine research and conservation.
Vaulted ceilings soar above ornate chandeliers, while beveled glass windows capture serene views of sprawling grounds framed by live oaks draped in Spanish moss. Outside, marble sculptures dot pathways leading to the Atlantic, where unspoiled beaches and dunes stretch endlessly.
5. Rockefeller Cottage – Jekyll Island, Georgia
The Rockefeller Cottage, also known as Indian Mound Cottage, is a three-story Gilded Age structure on Jekyll Island, Georgia. Built in 1892 by Gordon McKay and purchased by William Rockefeller in 1905, the house was designed as a winter retreat. Its architecture reflects a restrained Shingle Style, emphasizing woodwork and functionality.
The cottage’s 25 rooms include nine bedrooms, nine bathrooms, and seven servant quarters. Unique architectural features include an elevator, a cedar-lined walk-in safe, and a master bath equipped with taps for hot and cold saltwater.
The house sits near the iconic Jekyll Island Club, blending into the historic district’s understated elegance. Its name derives from a shell midden in the yard left by the Guale Mississippian Indigenous culture. After the island’s evacuation in 1942, the house eventually transitioned to public ownership in 1947 and was added to the National Register of Historic Places in 1971. Today, its restored interiors are accessible through guided tours by the Jekyll Island Museum.
4. Mount Hope Farm – Prudence Island, Rhode Island
Mount Hope Farm, built near the Mount Hope Bridge in Bristol, Rhode Island, is a layered architectural and historical tapestry that spans centuries. The estate, encompassing 211 remaining acres of what was once a much larger property, traces its roots back to the 1680s. The main house, a sprawling structure with origins in 1745, reveals its evolution through a mix of Colonial and mid-19th-century architectural styles.
The earliest section was crafted by Isaac Royall Jr., a prominent merchant whose wealth flowed from Caribbean plantations. In 1783, it passed to William Bradford, a U.S. senator and Rhode Island’s lieutenant governor, whose family held the property until 1837. Samuel W. Church, a merchant from Taunton, added his own touch with a substantial expansion in 1840, blending practicality with the architectural trends of his day. The estate’s next chapter began in 1917 under industrialist R.F. Haffenreffer, who did significant renovations.
3. South Bass Island Lighthouse – South Bass Island, Ohio
The South Bass Island Lighthouse, a striking Queen Anne-style beacon near Put-in-Bay, Ohio, has stood watch over Lake Erie since 1897. Built to navigate the crowded South Passage, its attached 60-foot light tower and red brick keeper’s dwelling marked a departure from traditional lighthouse designs, which often separated the tower from living quarters. The structure, laid in Flemish bond, was outfitted with modern comforts for its time: a full basement, laundry room, pocket doors, and a hot water reservoir.
Constructed for $8,600, the lighthouse was part of an effort to accommodate the growing tourist and commercial traffic spurred by the island’s booming wine industry and the grand Hotel Victory. A Fourth-Order Fresnel lens, added shortly after its opening, ensured a powerful beam to guide vessels.
Now owned by Ohio State University, the lighthouse serves as a research facility for Stone Laboratory. It earned a place on the National Register of Historic Places in 1990.
2. Singer Castle – Dark Island, New York
Singer Castle, formerly known as “The Towers,” rises from Dark Island in the Saint Lawrence Seaway like something out of a Gothic novel, complete with secret passageways, hidden panels, and a dungeon. Built between 1903 and 1905, the 28-room castle is an architectural statement by Ernest Flagg, the Beaux-Arts master responsible for some of America’s most ambitious structures, including New York’s Singer Tower. Frederick Gilbert Bourne, the self-made millionaire and president of the Singer Sewing Machine Company, commissioned this granite fortress as a hunting retreat and summer getaway for his family.
Constructed from tons of granite quarried on nearby Oak Island and shaped by Italian stonemasons, the castle features four stories, turrets, and tunnels. The south-facing boathouse housed a workshop, a powerhouse, and one of Bourne’s steam-powered vessels. Over 2,000 loads of Canadian topsoil transformed the rocky outcrop into lush grounds.
1. Shipman House – Hilo, Hawaii
The W.H. Shipman House, built on Hilo’s Reed’s Island, is a Victorian masterpiece. Designed in 1899 by Henry Livingston Kerr, a Honolulu architect, the house was constructed for its original owner, Jack Wilson, after an iron bridge connected the area to Hilo proper. The estate, crowned by a two-story round tower with a conical roof and curved glass panes, features wraparound verandas and lush tropical gardens. The ornate interior includes indoor plumbing and electricity.
The main house, guesthouse, servants’ quarters, and garage occupy an eight-acre lot, but it’s the small details that elevate it. The tower’s circular veranda adds a fairytale charm, while the grand parlor served as a stage for Queen Liliʻuokalani to play her compositions on the estate’s piano during her visits. The house hosted literary greats like Jack London during his five-week stay in 1907, when he wrote The Cruise of the Snark, and welcomed artist Georgia O’Keeffe in 1939, who found inspiration in its surrounding landscapes.
Listed on both state and national historic registers, the Shipman House is a rare fusion of Victorian elegance and Hawaiian history.
