Boldt Castle, New York. At the turn-of-the-century, millionaire George C. Boldt, set out to build a full size Rhineland castle in Alexandria Bay, on picturesque Heart Island. The grandiose structure was to be a display of his love for his wife, Louise. After she died suddenly, the castle and various stone structures were left to the mercy of the wind, rain, ice, snow and vandals, for 73 years. This is one of the outlying buildings, now restored, as is the castle itself.