🇨🇦 Canada · Ontario and the Great Lakes region
The Thousand Islands are one of the most singular and serene landscapes in Canada: an archipelago of more than one thousand eight hundred islands and islets scattered across the St. Lawrence River, right where Lake Ontario begins its long journey to the Atlantic. There are islands of every imaginable size: from small rocks with a single pine clinging to the stone, to large islands with forests, lighthouses, country houses and even castles. Winding capriciously between them runs the border between Canada and the United States.
In the late 19th and early 20th centuries, the Thousand Islands became fashionable among North America's millionaires, who built summer mansions and dream residences on them, including the famous Boldt Castle, raised by a hotel magnate as a gift, tragically unfinished, for his wife. That mix of nature, water and romantic history gives the region a particular charm. Today part of the islands are protected by Thousand Islands National Park, the smallest and most easterly national park in Ontario, managed by Parks Canada.
This guide covers the Thousand Islands with a practical eye: how and where to take a cruise, which castles and lookouts to visit, how to tour the region by car, by kayak or on foot, and how to combine it with the cities of Kingston and Brockville. It is an ideal destination for anyone after water landscapes, boat trips, quiet nature and a touch of history, in one of the most photogenic corners of eastern Ontario.
For thousands of years the Thousand Islands were the territory of the region's Indigenous peoples, above all Iroquoian-speaking (Haudenosaunee) nations and, later, Algonquian ones too, who fished and paddled among the islands of the St. Lawrence. A traditional story linked to these peoples gives one of the poetic explanations for the origin of the islands. With the arrival of the Europeans, the St. Lawrence became the great route into the interior of the continent: first the French of New France and then the British sailed these waters. After the independence of the United States, the border was drawn down the middle of the river, leaving islands on each side. In the late 19th century, with the spread of the railway and tourism, the Thousand Islands turned into a fashionable destination for high society from New York, Philadelphia and other cities, who built summer mansions and hotels on the islands. The great castles date from that golden age: Boldt Castle, begun in 1900 by the hotel magnate George Boldt as a gift for his wife Louise and abandoned after her death in 1904; and Singer Castle, on Dark Island. The region also gave rise, according to tradition, to the popular 'Thousand Island dressing'. In 1904, on the Canadian side, the park that would in time become Thousand Islands National Park (originally St. Lawrence Islands National Park) was created, one of the oldest and smallest in Canada, dedicated to protecting several islands and their rich biodiversity. The full history is on our history page.
Read the full history ↓Canada's economic and demographic heart: land of the Iroquoian and Algonquian nations, refuge of the Loyalists, cradle of Upper Canada and the country's industrial engine, home to Toronto, to the national capital Ottawa and to Niagara Falls.
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Origins, formation and what the sources say.
Long before the Europeans arrived, the waters of the St. Lawrence River and its maze of islands were the territory of the region's Indigenous peoples. Iroquoian-speaking (Haudenosaunee) nations and, at various times, Algonquian ones too, paddled between the islands, fished their waters and moved along the great river, one of the main arteries of communication in the northeast of the continent. For these peoples the islands were not an empty landscape but a known territory loaded with meaning.
One of the loveliest traditional explanations of the origin of the islands comes from the body of Indigenous stories. According to a widely told version, the Great Spirit had promised a paradise to the peoples who lived in peace; on seeing the nations turn on each other again, he gathered up the heavenly garden he had offered and, as he carried it away, dropped fragments over the river, which became the thousand islands. Hence the poetic name 'Garden of the Great Spirit' (Manitouana, in some versions) that has been given to the region.
Beyond the story, what is certain is that these islands were part of a rich and dynamic Indigenous world, crossed by trade routes, alliances and conflicts, over which the European presence would later be laid. The name of the town of Gananoque, of Indigenous origin, recalls that inheritance.
With the arrival of the Europeans, the St. Lawrence River became the great route into the interior of North America. The French of New France were the first to sail these waters in search of furs and trade routes, followed by explorers, missionaries and merchants. The Thousand Islands region, at the transition between Lake Ontario and the St. Lawrence, was an obligatory passage on that strategic corridor.
After the fall of New France and the establishment of British rule, and then after the independence of the United States, the region took on a feature that defines it to this day: the international border between Canada and the United States was drawn down the middle of the St. Lawrence River, literally winding between the islands. So some islands ended up in Canadian territory (Ontario) and others in American territory (New York State), sometimes only a few meters apart.
This river border, one of the most picturesque in the world, coexists with a long tradition of exchange between the two shores. Over time, international bridges, such as the Thousand Islands Bridge complex, would link the two countries across the islands, and the region would become a symbol of the relationship between Canada and the United States.
In the late 19th century, the Thousand Islands lived through their most glamorous period. The spread of the railway and of steamships brought the region closer to the great cities of the northeastern United States, and high society from New York, Philadelphia and other cities discovered in these islands a fashionable summer destination. Grand hotels, yacht clubs and, above all, luxurious summer residences began to go up on the islands, becoming a status symbol for the magnates of the golden age of American capitalism (the 'Gilded Age').
Out of that fervor came the famous island castles. The most celebrated is Boldt Castle, on Heart Island: in 1900, the hotel magnate George Boldt, owner of the Waldorf-Astoria in New York, had a lavish six-story castle built in the style of the Rhine castles as a gift for his wife Louise. Hundreds of laborers were working on it when, in 1904, Louise died suddenly. Devastated, Boldt ordered all work stopped at once and never went back to the island; the castle was left unfinished, turned into a melancholy monument to love cut short. Another notable castle is Singer Castle, on Dark Island.
From this golden age also comes, according to tradition, the popular 'Thousand Island dressing', whose origin is linked to the region and to its hotels and luxury residences. Although the splendor of those years faded with time, it left the islands a legacy of mansions, romantic stories and an aura of elegance that still draws visitors.
While the region was living through its tourist boom, an idea of conservation also began to take shape. In 1904, on the Canadian side, a national park was created to protect several of the islands of the St. Lawrence: St. Lawrence Islands National Park, one of the oldest national parks in Canada and the first east of the Rockies. In time it came to be called Thousand Islands National Park, the name it is known by today.
Managed by Parks Canada, the park is the smallest and most easterly in Ontario. It protects more than twenty islands and a stretch of the mainland shore, in an area of great ecological value: the islands sit on the so-called 'Frontenac Arch', a natural granite bridge that links the Canadian Shield with the Appalachian mountains and that allows an unusual biodiversity to coexist, with species of reptiles, amphibians, birds and plants that are uncommon in the rest of the province.
Through the 20th and 21st centuries, the park developed its visitor center at Mallorytown Landing and a network of islands with docks, trails and campsites, designed above all for those touring the region by kayak and canoe. The creation and consolidation of this park reflected a shift in how the Thousand Islands were seen: from a luxury summer landscape to a natural heritage worth protecting for future generations.
The 20th century slowly transformed the character of the Thousand Islands. The splendor of the 'Gilded Age' faded with the Great Depression, the wars and social change, and many of the great summer mansions changed hands, fell into disrepair or disappeared. But the region did not lose its appeal: the glamour of another era was replaced by a more democratic, family tourism, centered on river cruises, sport fishing, kayaking, boating and simply enjoying the landscape. Gananoque, on the Canadian side, established itself as the tourist capital of the islands, with its docks, its summer theater and its relaxed feel.
In 2002, the natural value of the region received international recognition: Unesco designated the Thousand Islands area and the Frontenac Arch as a Biosphere Reserve (Frontenac Arch Biosphere), one of the most biodiverse areas in all of Canada. The reason is at once geological and ecological: the Frontenac Arch is an ancient granite ridge that crosses the St. Lawrence and throws a natural bridge between the Canadian Shield and the Adirondack mountains, a corridor where as many as five different forest regions meet. That crossroads explains the surprising wealth of species, many of them rare or at the limit of their range, that live on the islands and their shores.
Today the Thousand Islands live in a delicate balance: on one side, an established tourist destination drawing visitors from Canada, the United States and the world to its cruises, castles and lookouts; on the other, a territory of great natural value that people are trying to preserve through Thousand Islands National Park, the biosphere reserve and conservation initiatives. That double character, a romantic landscape loaded with history and a sanctuary of biodiversity, is what makes the Thousand Islands a unique place in eastern Ontario.