Thousand Islands

Where the St. Lawrence turns into a scattered archipelago

The Thousand Islands region is the stretch of the St. Lawrence River, roughly between Kingston and Brockville, where the river widens and fractures into 1,864 islands, ranging from single-tree rock outcrops to islands large enough for full estates. The Canada–US border runs through the middle of the archipelago, which means the region’s history is as much about smuggling, Gilded Age wealth, and Cold War-era tension as it is about scenery.

Where	St. Lawrence River, ~3 hrs / 260 km from Toronto
Time needed	1-2 days
Getting there	VIA Rail to Kingston, or car via Highway 401
Cost	Cruises around CAD 40-90/person depending on route
Best time	Late May-September for cruises; early-mid October for foliage

The name undersells the number — there are actually more than 1,800 islands by the official count that defines an “island” as year-round land with at least one living tree — but the phrase “Thousand Islands” stuck in the 19th century and never let go, along with the salad dressing that was reportedly invented here by a local fishing guide’s wife.

Most visitors experience the region from the water: a river cruise out of Gananoque or Kingston is the standard way to see the islands up close, since many of the most interesting ones are privately owned and only visible from the water or a bridge.

Getting there from Toronto

The drive from Toronto to the region’s hub towns is about 3 hours (roughly 260 km) via Highway 401 east. VIA Rail runs direct trains to Kingston, which is the most practical rail-accessible base if you’d rather not drive; from Kingston, Gananoque is a 25-minute drive or a seasonal shuttle away, and Brockville is about 45 minutes further east.

If you’re combining a Thousand Islands trip with Prince Edward County, the drive between Picton and Kingston is about an hour, making a two-region loop realistic over a longer weekend. For a ready-made version of a full trip, the Thousand Islands getaway itinerary lays out a two-day plan across the cruises, Fort Henry, and the riverside towns.

Boldt Castle and the region’s Gilded Age history

Boldt Castle, on Heart Island (technically on the US side of the border), is the region’s best-known landmark — a six-story stone castle built in the early 1900s by hotel magnate George Boldt as a gift for his wife, left unfinished after her sudden death and only restored decades later by the Thousand Islands Bridge Authority. It’s accessible only by boat, which is why most visitors see it as part of a cruise rather than a standalone visit.

A 1000 Islands cruise with the option to stop at Boldt Castle departs from Gananoque and covers both the scenic route through the islands and, for those who add the castle stop, a couple of hours to walk the grounds and interior. Given that the castle requires a passport for the island stop (it’s US territory), confirm your documentation before booking that option.

For a shorter cruise without the castle stop, a scenic highlights cruise from Gananoque or Ivy Lea covers the core of the island cluster in under two hours — a good option if you’re tight on time or traveling with young kids who won’t sit still for a full castle tour.

The two-castle route from Ivy Lea

East of Gananoque, near the village of Ivy Lea, a different cruise route covers both Boldt Castle and Singer Castle on Dark Island — a stone mansion built for a Singer Sewing Machine Company executive that later served as a private retreat and, according to local lore, a possible rum-running waypoint during Prohibition. The two-castle scenic cruise from Ivy Lea is the way to see both landmarks on a single outing rather than booking two separate boat trips.

Kingston: the region’s largest town

Kingston, Ontario’s first capital, anchors the western edge of the region and functions as the practical base for most visitors — it has the rail connection, the widest choice of hotels, and its own historic core built around Fort Henry and the Kingston waterfront. Many Thousand Islands cruises also depart directly from Kingston, making it a viable alternative to Gananoque if you’re not driving.

Gananoque and Brockville: the smaller river towns

Gananoque, the traditional cruise-departure hub, is a compact town built almost entirely around its waterfront and the boat tour industry — most visitors pass through for a few hours around a cruise rather than staying multiple nights, though its Main Street has enough restaurants and shops for a pleasant afternoon. Brockville, further east, has a quieter, more residential feel and its own claim to fame as the birthplace of Canada’s first flag-raising ceremony, alongside a walkable historic downtown along the river.

The 1000 Islands Parkway

Rather than taking Highway 401 the whole way, the 1000 Islands Parkway runs along the river between Gananoque and Brockville, offering pull-offs and lookout points with views over the islands that the highway doesn’t provide. It’s a worthwhile detour of about 20–30 extra minutes if you’re driving between the two towns and want to see the archipelago from land as well as water.

Fort Henry and Cold War-era sites

Fort Henry, on the outskirts of Kingston, is a restored 19th-century fortress built to defend the entrance to the Rideau Canal from a feared American invasion that never came — today it runs historical reenactments and a summer sunset ceremony with military drills and music. The region also has quieter Cold War history: several islands and shoreline sites once played a role in border surveillance, though most of that history is now more folklore than formal tourism.

Choosing between the cruise options

Cruise	Length	Best for
Highlights scenic cruise	Under 2 hours	Tight schedules, young kids
Boldt Castle cruise	Half-day with the castle stop	First-time visitors wanting the signature landmark
Two-castle cruise from Ivy Lea	Half-day	Visitors who want both Boldt and Singer Castle in one trip

When to visit

Cruise season runs roughly late May through September, with Boldt Castle typically open to visitors during the warmer months and closed over winter. September offers a strong combination of good weather, thinner crowds than peak summer, and the start of fall color along the riverbanks, which tends to peak in early-to-mid October.

Practical notes

A passport is required for any cruise stop that lands on Boldt Castle or Singer Castle’s islands, since both are on the US side of the border, even though the boats themselves depart from Canadian towns. Water levels and cruise schedules can shift with weather, so confirming departure times the day before is worth the extra step during shoulder-season trips. Hotel supply in Gananoque is limited relative to Kingston, so booking ahead matters more if you’re set on staying in the smaller town.

Frequently asked questions about Thousand Islands

Do I need a passport to visit the Thousand Islands?

You don’t need one to visit the Canadian towns (Kingston, Gananoque, Brockville) or to take a scenic cruise that stays on the water. You do need a passport if your cruise includes a stop at Boldt Castle or Singer Castle, since both islands are US territory.

How many islands can you actually see on a cruise?

Most standard cruises pass dozens of islands over a one-to-two-hour route, though the full archipelago spans a much wider stretch of the river than any single cruise covers. Longer cruises and the two-castle route cover more ground than the shorter highlights tours.

Is Kingston or Gananoque the better base for visiting?

Kingston has more accommodation, restaurants, and its own historic sites (Fort Henry, the waterfront), plus direct VIA Rail access, making it the more practical base for most visitors. Gananoque is closer to the main cruise departure points and works well for a shorter, cruise-focused visit.

What’s the best month to see the islands?

June through September for full cruise schedules and warm weather; early-to-mid October for fall color along the river, though some cruise operators wind down their schedules by then.

Can I visit the Thousand Islands without a car?

Partially — VIA Rail reaches Kingston directly, and from there, taxis, seasonal shuttles, or short drives connect to Gananoque’s cruise docks. Brockville and the more remote parts of the region are harder to reach without a car.

Is Boldt Castle worth the extra cost and time?

For most visitors, yes — it’s the region’s signature landmark and the story behind its construction (and its owner’s abandonment of the project after his wife’s death) adds context that a purely scenic cruise doesn’t provide. Families with very young children or travelers on a tight schedule may prefer the shorter scenic-only cruise instead.

Can I do the Thousand Islands as a day trip from Toronto?

It’s possible but tight given the 3-hour drive each way — most visitors get more out of an overnight stay in Kingston or Gananoque, which allows time for a cruise plus Fort Henry or a riverside walk without an exhausting same-day round trip.

Should I book Boldt Castle or the two-castle cruise?

Choose Boldt Castle alone if you want a shorter outing focused on the region’s best-known landmark; choose the two-castle cruise from Ivy Lea if you’d rather see both Boldt and Singer Castle in a single half-day trip and don’t mind the slightly longer time on the water.