Discover the Best Thousand Islands Tours

This group of 1,864 islands are located in the St. Lawrence River on the United States-Canadian border and extend for approximately 50 miles. Thousand Islands, or 1,000 Islands, were formed nearly 12,000 years ago and discovered by Jacques Cartier with the St. Lawrence River in 1535. They were a popular vacation destination for many upper and middle class families, who often built homes and mansions there, during the late 19th Century and early 20th Century. The 27-mile Wolfe Island located in Ontario is the largest island. Notable sights are the Boldt Castle, Singer Castle, Cornwall Brothers Museum, Wellesley Island State Park, Thousand Islands National Park, Thousand Islands Bridge, Robert Moses State Park, Antique Boat Museum, Eel Bay, Rock Island Lighthouse and St. Lawrence statue.