Boldt Castle

Boldt Castle is a major landmark and tourist attraction in the Thousand Islands region of the U.S. state of New York. Open to guests seasonally between mid-May and mid-October, it is located on Heart Island in the Saint Lawrence River. Heart Island is part of the Town of Alexandria, in Jefferson County. Originally a private mansion built for American millionaire George Boldt, it is now maintained by the Thousand Islands Bridge Authority as a tourist attraction.