2 Best Sights in Alexandria Bay, The Adirondacks and Thousand Islands

George C. Boldt, proprietor of the Waldorf-Astoria Hotel in New York, began building this 120-room Rhineland-style castle on Heart Island for his wife, Louise, in 1900. Four years later, when she died suddenly, he ceased work on the castle. The building remained deserted for 73 years, abused by vandals and weather. Since 1977, millions of dollars have been poured into restoration work. It's worth a trip to the 5-acre island to see the castle. Its fleet of wooden boats is in the Boldt Yacht House, on Wellesley Island. Uncle Sam Boat Tours runs shuttle boats between Alexandria Bay, Heart Island, and Wellesley Island.

Guides lead 45-minute tours, up and down many stairs, through this lovely turn-of-the-20th-century castle on Dark Island. The castle, originally known as the Towers, was built as a summer home for Frederick G. Bourne, president of the Singer sewing-machine company. Famed American architect Ernest Flagg modeled the four-story, 28-room structure on a Scottish castle, giving it all sorts of interesting nooks and crannies. To get here, take a boat from Alexandria Bay. Empire Boat Lines and Uncle Sam Boat Tours include Singer Castle in their sightseeing cruises.