Dark Island, a prominent feature of the Saint Lawrence Seaway, is located in the lower (eastern) Thousand Islands region, near Chippewa Bay. It is a part of the Town of Hammond, in St. Lawrence County, New York. An historic landmark here, "The Towers" was long known as Dark Island Castle until recently renamed "Singer Castle". The island is situated only a few yards south of the Canada-United States border that runs along the river.