|Location||80 Hesperus Ave., Gloucester, Massachusetts|
|Architect||John Hays Hammond, Jr.|
|NRHP reference #||73000298|
|Added to NRHP||May 08, 1973|
Hammond Castle is located on the Atlantic coast in the Magnolia area of Gloucester, Massachusetts. The castle, which was constructed between 1926 and 1929, was the home and laboratory of John Hays Hammond, Jr. He was an inventor who was a pioneer in the study of remote control and held over four hundred patents. The building is composed of modern and 15th-, 16th-, and 18th-century architectural elements and sits on a rocky cliff overlooking Gloucester Harbor.
At present, the castle operates as the Hammond Castle Museum, displaying Hammond's collection of Roman, medieval, and Renaissance artifacts as well as exhibits about his life and inventions. The Great Hall contains a huge pipe organ which has been used for concerts and recordings by many famous organists including Richard Ellsasser and Virgil Fox. Unfortunately, as of 2015, the organ is no longer functional. Tours are self-guided, and visitors may explore eight living areas (including a dining room and bedrooms), an inner courtyard, two towers and the Great Hall.
The castle's lawn overlooking the harbor serves as a location outside of museum hours for weddings and various other private functions. For the past 25 years, the castle has run a special Halloween-themed haunted house tour every October. Volunteers for the production include high school students from Cape Ann (the North Shore region). The Halloween fundraiser attracts thousands of visitors per year.
- National Register of Historic Places listings in Gloucester, Massachusetts
- National Register of Historic Places listings in Essex County, Massachusetts
- American Castles, by Julian Cavalier, published 1973, pages 15–287.