Dark Island is a Saint Lawrence River island near Chippewa Bay, just south of the Canada-United States border, best known for Singer Castle. Designed largely by Ernest Flagg for Singer Manufacturing Company president Frederick Gilbert Bourne and planned in 1903, the house was modeled on an English castle and became one of the last Thousand Islands castles of the region’s resort-building era. Expanded by Marjorie Bourne Thayer in 1928, it is noted for its 28 rooms and concealed passageways. After changing owners and serving briefly under the name Jorstadt Castle, the property was restored after 2001 and opened for public tours in 2003.