Boldt Castle

Admission is $14.00 for an adult, $10.00 for a child aged 5–12, and free for children 4 and under. The Boldt Yacht House is a separate $8.50 adult, or you can buy a combination ticket for both at $17.00 adult / $10.00 child, which saves an adult $5.50. What those figures do not include is the boat: Heart Island is only reachable by water, and the fare is a separate purchase. Budget roughly $24 an adult all-in from Alexandria Bay, or about $27 with the Yacht House.

No, and this is the single most common surprise. The Alexandria Bay shuttle run by Uncle Sam Boat Tours states plainly that Boldt Castle admission is sold separately; its own fare was last published at about $10.00 adult and $6.50 child for the ten-minute crossing. Cruises from the Canadian side work the same way — several sell castle entry as an option rather than including it. Always read whether a boat ticket says entry is included.

Boldt Castle is an official US port of entry, so arriving from the Canadian side means formally entering the United States and providing proper identification. The Bridge Authority says so directly. What counts as acceptable identification is set by US Customs and Border Protection, not by the castle or the boat operator, so check CBP's current traveller guidance rather than relying on what a ticket seller tells you. The border desk on the island operates 10:30 am to 5:30 pm.

Only by boat — there is no bridge or causeway to Heart Island. From the American side, a shuttle runs from Alexandria Bay and takes about ten minutes, departing roughly every half hour from 10:30 am. From the Canadian side — Gananoque, Rockport, Ivy Lea, Kingston — you take a scenic cruise, which takes between one and five hours depending on the route and doubles as the sightseeing. Some visitors also arrive on their own boat; the island has docking.

No. Uncle Sam Boat Tours states that Boldt Castle Shuttle tickets are only available at its ticket booth from 9:00 am and cannot be bought online or in advance. That is worth planning around on a summer weekend, because it means queueing on the day. It is also the clearest practical argument for a pre-booked cruise from the Canadian side, or a pre-booked entry ticket: those you can hold before you arrive.

The 2026 season runs May 9 to October 12, daily 10:30 am to 6:30 pm, with the admissions booth closing one hour before the castle. Independence Day weekend runs later — until 7:30 pm on Friday July 3rd and Saturday July 4th. The castle is closed outside the season entirely. If you are crossing from Canada, the binding constraint is not the castle's hours but the port of entry's, which shut at 5:30 pm.

It is a separate building on a separate island, and the shuttle boat between them is free — which is the part most visitors do not realise. The Yacht House stands on Wellesley Island, holds slips 128 feet long built for the Boldt fleet, and is on the National Register of Historic Places. Bought alone it is $8.50; bought with the castle it adds only $3.00 to a $14.00 ticket. If you have the time in your crossing, the combination ticket is the obvious buy.

George C. Boldt stopped construction in January 1904 when his wife Louise died, and never came back. He had begun in 1900, with 300 workers building a six-storey, 120-room castle on Heart Island as a gift to her. The telegram ordering work to stop ended it. The building was left open to the weather for seventy-three years until the Thousand Islands Bridge Authority acquired it in 1977 for one dollar, on the condition that revenue went into restoration. Some rooms are restored; others are deliberately left as they were found.