Constructed between 1926 and 1929, was the home and laboratory of John Hammond. The castle was constructed as a wedding present for his wife Irene Fenton.
In the Castle he produced over 400 patents and the ideas for over 800 inventions (second only to Thomas Alva Edison in number of patents). The exterior of the castle is built from granite mined from the nearby hillsides, known as Cape Ann granite, the windows, doorways and much of the interior of the structure are actual pieces of European castles, churches and buildings Hammond bought and shipped to the United States.
Hammond also added some unique features to the structure such as an indoor pool that can be drained with a flip of a switch and filled with sea water, rooms with hidden doors, secret passageways, a library with a whispering ceiling and an inner courtyard that was once outfitted with special overhead pipes and wiring to simulate rain or twinkling stars
