George Boldt halted construction on Heart Island in 1904, the day his wife Louise died. For seven decades the six-story Rhineland castle stood unfinished, its turrets open to snow and rain, until the Thousand Islands Bridge Authority acquired the property in 1977 and began a restoration that continues today.
The 120-room structure was conceived as a surprise gift — Boldt, who managed New York's Waldorf-Astoria, commissioned Philadelphia architect G. W. Hewitt to design a full-scale Rhineland fortress on a five-acre island in the narrowest channel of the St. Lawrence. By the time work stopped, masons had laid Italian marble floors, carved oak staircases spiraled four stories, and a separate powerhouse island had been built to supply electricity without marring the romantic silhouette.
Today the castle receives more than 125,000 visitors each season, arriving exclusively by private boat or aboard scheduled thousand island cruise to boldt castle departures from Gananoque, Ivy Lea, and Brockville. The St. Lawrence Seaway splits the border here — Heart Island sits on the American side, five hundred meters from the Canadian shore — so every approach crosses international water. The Boldt Yacht House, completed in 1900, remains the only structure George saw finished; its second-floor ballroom and ground-level boat slips now host interpretive exhibits on the family's original vision. Restoration crews have rebuilt the castle's slate roof, replaced limestone balustrades on the upper terraces, and reopened the Alster Tower, a defensive folly modeled on a medieval Rhine watchtower. Conservators estimate another decade of work remains on the interior suites, funded entirely by the fourteen-dollar admission fee and private donations.
The island's gardens, originally planted by landscape architect Ernest W. Bowditch, were designed to bloom in sequence from May through October, ensuring color on every terrace throughout the season. A dedicated groundskeeping team maintains thirty thousand annuals and perennials across formal beds, woodland paths, and the children's playhouse garden. Thousand island cruise to boldt castle tickets include the full-day admission pass; most vessels offer two or three return sailings, allowing passengers to control their duration on Heart Island. The castle complex encompasses the main residence, the yacht house, the Alster Tower, and the stone arch bridge connecting to the powerhouse island — together they form the most complete surviving example of Gilded Age island estate planning in the Great Lakes-St. Lawrence basin.
5 hr
