The Thousand Islands: Boldt Castle, boat tours and river towns

This guide is for Central New York readers planning a day trip or a long weekend on the St. Lawrence River, where Interstate 81 crosses the Thousand Islands Bridge to the Canadian border. It covers Boldt Castle and the Boldt Yacht House, the boat tours that get you there, and four river and lake towns: Alexandria Bay, Clayton, Cape Vincent and Sackets Harbor.

Timing matters here. Most of what draws visitors runs from May into mid-October, and the 2026 season for the castle ends on October 12. The sections below give the dates each place has posted, so you can tell what is still open on a fall drive and what has to wait for spring.

The castle on Heart Island and the Yacht House

George C. Boldt, the millionaire proprietor of New York City’s Waldorf Astoria hotel, started building Boldt Castle on Heart Island off Alexandria Bay in 1900 for his wife, Louise. She died before the castle was finished, he stopped work, and the stone shell sat empty for 73 years. The Thousand Islands Bridge Authority bought the property in 1977 and has put the castle’s net revenue back into restoring it ever since.

Heart Island is reachable only by water, by tour boat or private boat. The 2026 season runs May 9 to October 12, 10:30 a.m. to 6:30 p.m., and the admissions booth closes an hour before the castle does. Castle admission is $14 for ages 13 and up and $10 for ages 5 to 12; children 4 and under are free. A package that adds the Yacht House is $17 for adults and $10 for children. Prices are in U.S. funds, and the castle takes major credit cards and U.S. cash.

The Yacht House sits across the channel on Wellesley Island, and a free shuttle boat runs there from Heart Island. The building rises 64 feet and has boat slips 128 feet long. Inside are antique wooden boats on loan from the Antique Boat Museum in Clayton, some from the original Boldt fleet, along with the Kestrel, an 1892 steam yacht. The Yacht House opened to the public in 1996 and is listed on the National Register of Historic Places.

A few practical points from the castle’s visitor page:

• Heart Island is in the United States and is an official U.S. port of entry. Passengers arriving on tour boats from Canada must show proper identification.
• Pets are not allowed on Heart Island or at the Yacht House, except registered service animals.
• The castle has no climate control, so dress for the day’s weather.

Boat tours from Alexandria Bay and Clayton

The castle shuttle and cruises from Alexandria Bay

From Alexandria Bay, the 10-minute castle shuttle is run by Uncle Sam Boat Tours, a family-owned company that has run cruises from Alexandria Bay since 1926. Parking is free at 45 James St., with attendants directing cars into the lots on busy days. The shuttle leaves every half hour starting at 10:30 a.m. on days the castle is open; the adult fare is $10, and castle admission is sold separately. Shuttle tickets are sold only at the ticket booth, which opens at 9 a.m., and boats stop carrying passengers to Heart Island about 90 minutes before the castle closes.

The company also runs longer narrated cruises, including a 2 Nation Tour ($32 for adults) that loops through U.S. and Canadian waters. The FAQ on the company’s website says no passport or visa is needed for any tour, because passengers never step onto Canadian soil.

Small-boat tours from Clayton

Upriver, Clayton Island Tours sails from 39611 Chateau Lane in Clayton on boats that carry 43 to 65 passengers. Clayton Island Tours’ Boldt Castle and Two Nation Tour runs about three and a half hours with a stop on Heart Island. The company also runs a glass-bottom boat, the Night Heron, to Rock Island Lighthouse State Park, a trip the company bills as the only public tour to the lighthouse. The 2027 schedule is already posted, with the castle tour running May 8 to October 11, 2027.

A second castle on Dark Island

The river’s second castle, Singer Castle on Dark Island, sits near Chippewa Bay, northeast of Alexandria Bay. Architect Ernest Flagg designed the castle for Frederick Gilbert Bourne, the fifth president of the Singer Sewing Machine Company, and crews built it from 1903 to 1905. Guided tours take about 45 minutes and include 80 steps up from the Great Hall. Adult admission is $14.75. For fall 2026 the castle is posted as open weekends through October 11 and mornings on October 17 and 18, with Uncle Sam Boat Tours leaving Alexandria Bay at 9:45 a.m. Call ahead, because the castle says early and late season hours can change.

Clayton: boats on land and on the water

Clayton is about 15 minutes from Alexandria Bay, according to the state’s I LOVE NY travel-time chart. The Antique Boat Museum at 750 Mary Street opened for 2026 on May 9 and keeps daily 10 a.m. to 5 p.m. hours through October 12, the museum’s last day of regular operation, then opens weekends for the rest of October. The museum suggests planning at least an hour and a half.

The museum has two add-ons. La Duchesse, a 106-foot houseboat built in 1903 for George Boldt, has 30-minute guided tours every hour from 10:30 a.m. to 3:30 p.m.; sign up at the admissions desk when you arrive, and note the houseboat is not wheelchair-accessible. Ride the River puts up to six passengers in Miss Thousand Islands III, a 30-foot triple-cockpit Hacker Craft, for a 45-minute run past Rock Island Lighthouse and Calumet Island. Adult rides are $41 and include museum admission. The museum’s posted 2026 schedule has weekend rides at 1, 2 and 3 p.m. from October 17 through November 1, weather permitting.

The museum’s 62nd Antique Boat Show & Auction ran July 31 to August 2, 2026; check the museum calendar for 2027 dates.

Next door, Wood Boat Brewery at 625 Mary St. pours beer brewed on site, including “Pardon Me” Pale Ale and “Old Town” Oatmeal Stout, alongside brick-oven pizza. There is an outdoor deck on the river side and a pub-style dining room for cooler months. The brewery is open seven days a week, with shorter kitchen hours in fall and winter.

Alexandria Bay: where to stay on the water

The village of Alexandria Bay faces Heart Island across the water, and two large waterfront hotels sit on Holland Street.

On the waterfront, Riveredge Resort Hotel at 17 Holland Street was built on an old steamboat wharf and has water on three sides. The hotel has an indoor pool and fitness room, plus the Windows on the Bay restaurant and dock space for guests arriving by boat.

Also on Holland Street, Bonnie Castle Resort & Marina at No. 31 has decks overlooking Boldt Castle on Heart Island. Dinner is in the Manor House Restaurant and the Riverside Sports Bar, and The Pointe Bar & Grill on the dock is seasonal. The resort’s 2026 summer concert series ran tribute-band shows in August and early September with 600 seats per show.

Cape Vincent: where the lake meets the river

Cape Vincent sits at the entrance to the St. Lawrence River, where Lake Ontario flows into the river. Tibbetts Point Lighthouse marks that entrance. The lighthouse grounds are open year-round, 24 hours a day, and the town’s website pitches the point for watching sunsets. The lighthouse historical society posts visitor center and museum hours on the society’s calendar, and says the light still uses the only classical Fresnel lens operating on Lake Ontario.

For dinner in the village, Channel Marker 243 at 427 S. Market St. is a restaurant, bar and motel and a sister location of Wood Boat Brewery, with that brewery’s beer on tap. The kitchen is closed Mondays and opens at 4 p.m. Tuesday through Friday, so check before you drive out.

One change for 2026: the seasonal car ferry from Cape Vincent to Wolfe Island, Ontario, did not run this summer. WWNY reported in May that officials hope to restore it in 2027, with reopening the Canadian port of entry as the main hurdle.

Sackets Harbor: the War of 1812 on Lake Ontario

Sackets Harbor, on Black River Bay southwest of Watertown, was a U.S. Navy base during the War of 1812 and saw two battles, on July 19, 1812, and May 29, 1813. The Sackets Harbor Battlefield State Historic Site at 504 W. Main Street has restored 1850s Navy Yard buildings and the Commandant’s House. The grounds are open year-round until dark. For 2026 the buildings are open Saturdays through October 10, 10 a.m. to 4:30 p.m.; admission is $5 for adults, $3 for seniors and students, and free for children 12 and under.

Families heading that way can add Old McDonald’s Farm in the Town of Hounsfield outside the village. The farm marked 40 years in business in 2026, and a co-owner told WWNY the farm has about 200 animals, hay rides, mini golf and goats to feed, with a corn maze and pumpkin patch in the fall. The farm is seasonal, so check the farm’s schedule before late-fall visits.

Good to know

These dates and rules were checked on October 2, 2026:

• Boldt Castle and the Yacht House close for the season on October 12, 2026. In the off-season the castle office number is (315) 482-2501.
• The Antique Boat Museum’s regular season also ends October 12, with weekend hours for the rest of October.
• Singer Castle’s last posted 2026 dates are October 17 and 18, mornings only.
• Driving into Canada over the Thousand Islands Bridge requires border documents such as a U.S. passport book, passport card or NEXUS card. The State Department’s Canada page lists what is accepted and advises carrying a copy of each child’s birth certificate. Boat tours that do not land in Canada do not require a passport.
• The Cape Vincent to Wolfe Island ferry did not operate in 2026.

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