Boldt Castle at a glance
Boldt Castle is on Heart Island, in US waters at Alexandria Bay. There is no bridge or road. You arrive by tour boat or private boat, and the castle ticket is a separate purchase from the boat ride.
The castle is seasonal. The 2026 season ran from 9 May to 12 October, daily from 10:30 to 18:30, with ticket sales closing one hour earlier. The next opening is announced for 8 May 2027. For the boat side, see our Thousand Islands boat tours guide.
Our picks: Boldt Castle tours
The 2026 season has ended and the castle is announced to reopen on 8 May 2027, so these are for planning. Castle admission is included only in the long options: the 5-hour cruise from Clayton, and the Gananoque and Rockport options that start in Canada.
Hand-picked tours, booked through Viator and GetYourGuide. Prices are indicative starting prices in US dollars (as of October 2026). Tap a tour for live availability and the current price in your currency.
Boldt Castle and Rock Island cruise with picnic lunch
- Boldt Castle admission
- Rock Island Lighthouse admission
- Picnic lunch
The castle ticket is already in the price, and you walk on two of the islands. A naturalist guide is on board.
Check availability →
Gananoque cruise with an optional Boldt Castle stop
- Boldt Castle entry, 5-hour option
- English and French audio commentary
The boat leaves from Canada, so you cross the border before boarding. Only the 5-hour option includes Boldt Castle admission, and it needs a passport or NEXUS card plus US border processing.
Check availability →
Rockport cruises with Boldt Castle and Yacht House options
- Castle entry, 4 and 5-hour options
- Yacht House entry, 5-hour option
The 1-hour trip is a cruise only, and the castle visits need a passport or NEXUS card plus US border documents. Departure is in Canada.
Check availability →Boldt Castle boat tours and combo trips
Boat trips with a Heart Island stop and castle cruises from the river towns, with live prices and availability.
Boldt Castle tickets and prices
Admission in USD for 2026. The ticket is paid on the island and does not include the boat.
| Ticket | Adults and ages 13 up | Children 5 to 12 | Ages up to 4 |
|---|---|---|---|
| Castle | $14 | $10 | Free |
| Yacht House only | $8.50 | $6 | Free |
| Castle and Yacht House | $17 | $10 | Free |
Tickets are not refundable and stay valid for 2 years from the purchase date. Plan to see the castle and the Yacht House? The combined ticket at $17 for adults is the better value than buying the two separately. For most visitors, the castle ticket alone is enough for a first visit, and the Yacht House makes sense if you like historic wooden boats.
Heart Island: how to get there
Six ways to reach the island, all by water.
| Option | From | What to know |
|---|---|---|
| Two Nation Tour | Alexandria Bay | 2¼ hours, optional Heart Island stop at the end when the castle is open. $32 adults, $22.50 children. |
| Mainland shuttle | Alexandria Bay | Boat ride to the island only. About $10 for adults and $6.50 to $7 for children. Check the current timetable. |
| Singer Castle tour | Alexandria Bay | 3½ hours, optional Boldt stop at the end in season. $50.75 adults, $34.25 children. |
| Boldt Castle and Two Nation Tour | Clayton | 3½ hours. Listed for the 2027 season at $31 adults and $19 children. |
| Stopover cruise | Gananoque, Canada | A 5-hour cruise with a Boldt stop is listed. You need the right entry papers for Heart Island. |
| Private boat | Your own boat | Allowed. The island is a US port of entry. |
For most visitors without their own boat, a tour with a Heart Island stop is the simplest choice. Use the mainland shuttle if you only want to cross and have a day to spend on the island. The shuttle is a paid ride. The free shuttle at the castle is something different and described below.
The Boldt Yacht House
The Yacht House is a separate building on Wellesley Island, not on Heart Island. A free shuttle runs there from Heart Island. That shuttle does not replace the paid trip from the mainland to the island.
It shows historic wooden boats, some of them from the Boldt fleet, and the steam yacht Kestrel. The collection is shown in cooperation with the Antique Boat Museum. To see more boats, the Clayton page covers the museum itself.
Before you go
Rules, hours and borders.
Season and hours
The 2026 season ran from 9 May to 12 October, daily from 10:30 to 18:30. Ticket sales close 1 hour before the castle. There is no winter opening, so plan a visit between May and October.
Border check
Heart Island is a US port of entry. Border processing runs from 10:30 to 17:30, a time window of its own next to the castle hours. Guests who arrive from Canada by boat need proper entry papers and must meet US entry rules. A passport alone is not enough for every nationality.
Food, drink and pets
Food and drink are not allowed inside the buildings. Alcohol is not allowed on the grounds, except at licensed special events. Pets are not allowed, but service animals are.
Closures
The island can close for short periods because of weather, construction or safety.
The grounds include more than the main castle: the stone Power House with its pointed turrets also stands on Heart Island. Our Singer Castle guide covers the second castle you can visit by boat in the region.
Boldt Castle: frequently asked questions
How much are Boldt Castle tickets?
In 2026, castle admission is $14 for ages 13 and up and $10 for ages 5 to 12. Children up to 4 are free. The Yacht House costs $8.50 and $6, and the combined ticket costs $17 and $10.
Is Boldt Castle open in winter?
No. It is a seasonal visit. The 2026 season ended on 12 October, and the next opening is announced for 8 May 2027.
Does the boat ticket include the castle?
No. The boat fare and the castle admission are separate. A tour with a Heart Island stop lists the castle ticket as an extra.
Can I drive to Boldt Castle?
No. Heart Island can be reached only by water, by tour boat or private boat.
Do I need a passport for Boldt Castle?
Heart Island is a US port of entry. Guests who arrive from Canada need proper entry papers. If you start on the American shore with a tour that has no stop abroad, check the operator's rules for your trip.
Is this the official Boldt Castle website?
No. It is an independent guide with no connection to the castle's operators or the boat companies. Check current hours and prices with them before you travel.