Sport Island sits in New York’s Thousand Islands, the St. Lawrence River archipelago along the Canadian border that became one of the Gilded Age’s fashionable summer destinations. Built around 1880 for a prominent Pennsylvania railroad-industrialist family, the property has since undergone a substantial partial restoration.

The private island offers 1,110 acres of Scottish wilderness—and a castle to restore, built by an Antarctic explorer whose architect is believed to have sank with the Titanic.

Gråskär is a 2.6-hectare / 6.4-acre private island in the Finnish archipelago, offered with a prepared master plan and the chance to create a design-led cabin retreat inspired by the world of Project Ö.

For less than the price of many luxury apartments in New York City, buyers can purchase a private island with a 1912 cottage in Connecticut's Thimble Islands.

Built for Louise Grace—daughter of NYC’s two-time mayor and shipping magnate William R. Grace—this stuccoed Renaissance Revival cottage is a rare surviving example of an early American summer estate, set on 3,570 feet of private Maine shoreline.

Home to the Branson Beach Estate, Richard Branson acquired the 120-acre Moskito Island to preserve its natural beauty and establish a community of like-minded homeowners, each with a private three-acre lot and access to shared island amenities.

Home to a Neo-Gothic castle, lush gardens, and a storied past of hosting Nobel laureates and visionaries, this private island on Brittany's Pink Granite Coast was crafted in 1895 by pioneering Lithuanian-Polish inventor Bruno Abdank-Abakanowicz.

Discover Rogers Island, an exclusive private retreat on Long Island Sound, boasting a historic Tudor mansion, resort-style luxuries, and three private beaches—just minutes from the mainland.

The private island is located in the Angra dos Reis archipelago about 2 hours south of Rio de Janeiro. Known as the Green Coast of Brazil, the 365-island paradise is famous for its lush greenery and emerald green waters with over 2000 beaches.

A 20 minute boat ride from Venice, the 75 acre private island is the only of its kind in the Venice lagoon: a five-star fully-serviced luxury retreat complete with a resident chef and waiter, as well as a private boat with driver.