When you hear "Thousand Islands," you might think of a jar of salad dressing, but the namesake of that creamy condiment is one of North America"s most enchanting regions. The Thousand Islands form an archipelago in the St. Lawrence River, spanning the state of New York and the province of Ontario. It is made up of more than 1,800 islands. Some of these islands have fairytale castles; others are barely big enough for a hammock. There"s also Just Room Enough Island, which lives up to its name with a single house and a lone tree.