Hotel owner George C. Boldt renamed Hart Island in the St. Lawrence River to Heart Island, then set out to build a six-story, 120-room castle on it for his wife, Louise, according to 1000islands.com.
Boldt came to the United States from Prussia in the 1860s as the son of poor parents, the site says. He later owned the Waldorf-Astoria Hotel in New York City and the Bellevue-Stratford in Philadelphia.
He commissioned the castle in 1900, replacing a smaller summer cottage, NNY360 reported. About 300 workers, including stonemasons, carpenters, and artists, built it, according to the castle’s official history.
Boldt’s wife, Louise Kehrer Boldt, died suddenly in January 1904, months before the castle was finished. Boldt telegrammed the island to stop all construction, and the workers left. He never returned to Heart Island and died in 1916.
Advertisement
Advertisement
The unfinished castle sat vacant for decades. In 1977, the Thousand Islands Bridge Authority bought Heart Island and the nearby yacht house for $1, NNY360 said. Under the agreement, all revenue from the castle would go toward restoration.
As of 2020, more than $50 million had been spent on restoring and rehabilitating the castle and surrounding structures, per NNY360. The Thousand Islands Bridge Authority still owns and runs the castle and the Boldt Yacht House.
Boldt Castle is not the only landmark to be brought back after years of neglect. Michigan Central Station sat abandoned in Detroit for decades before Ford restored it.
This story was originally published by Parade on Oct 24, 2026, where it first appeared in the News section. Add Parade as a Preferred Source by clicking here.
