One of North America's most spectacular waterways — the St. Lawrence River's Thousand Islands region has 1,864 islands ranging from bare rocks to island estates, the Boldt Castle on Heart Island, and the international border running between Canadian and American islands. River cruises from Gananoque or Kingston cover the best of the archipelago.
Neighbourhood: Gananoque / Kingston (2.5h from Toronto) · Address: Gananoque, ON (2.5h from Toronto via Hwy 401) · Hours: Cruises: May–October | Multiple daily departures
Why Visit
Take in over 1,800 islands, ranging from tiny wooded islets to old-money mansions, as you cruise the St. Lawrence River — all just a couple hours from Toronto. Expect dramatic water views, the elaborate Boldt Castle, and a unique border-straddling landscape you can't get in the city.
What Makes It Unique
Unlike Toronto's harbour cruises, these trips actually weave between hundreds of rocky islands, some so small you’ll blink and miss them, others with castles and 19th-century homes. Nowhere else near Toronto can you find an international waterway where your boat drifts in and out of U.S. and Canadian waters, with customs only required if you disembark.
If you want an easy day trip from Toronto that feels completely different from the city, the 1000 Islands River Cruise is a really good call. It’s about 2.5 hours east via the 401, usually from Gananoque or Kingston, and once you’re there, the whole landscape changes. The St. Lawrence is wide, bright, and full of these scattered islands that seem almost unreal at first—1,864 of them, from tiny rocky outcrops with a single wind-bent pine to full-on island estates with boat houses and long docks. What makes it especially fun is that this isn’t just pretty scenery. The international border literally cuts through the water, so as you cruise along, you’re gliding between Canadian and American islands without it feeling dramatic at all.
I’d tell you to do one of the longer cruises, ideally the 3-hour one, because the shorter trips are nice but they can feel a bit like you just got into the rhythm of the river and then it’s over. The longer route gives you time to really take in the archipelago, pass the fancy cottages and old summer homes, and get that constant low-key commentary about who built what, which islands are privately owned, and how people actually live out there. It’s not a luxury yacht situation. It’s more straightforward sightseeing boat, open decks, people moving around for photos, kids pointing at castles, and everyone quietly trying to get a better view when the big landmarks come into sight.
And the big one is Boldt Castle on Heart Island. Even if you’ve seen photos, it’s stranger and more affecting in person. It’s a 120-room castle started in 1900 by George Boldt for his wife Louise, then abandoned on Valentine’s Day in 1904 when she died suddenly. That story could sound overly dramatic if it weren’t attached to an actual unfinished castle sitting out there in the river. It gives the place this odd mix of romance and sadness that people really do feel when they visit. If your cruise includes the stop, get off and do the tour. The grounds are beautiful, the rooms are impressive, and walking around Heart Island is half the appeal. It’s not huge, but it’s memorable.
A couple practical things. If you’re doing the castle stop, bring your passport since Heart Island is on the U.S. side. Book ahead in summer because those cruises fill up fast, especially on weekends. Try for a morning or early afternoon departure so the light’s better for photos and you’re not squinting the whole time. Sit outside if you can, but bring a layer—the wind off the river can be surprisingly cool even on hot days. And if you’re choosing between Gananoque and Kingston, Gananoque feels more cruise-focused and simple, while Kingston gives you more to do before or after.
I’d go back just for the approach to Boldt Castle alone. It’s one of those places that actually sticks with you after the day’s over.