Acton Castle

Acton Castle is a Grade II* listed structure with a central tower flanked by two wings, built from brick faced with local Cornish granite. The building is topped with embattled parapets and sits on a site overlooking St Michael's Mount and the bay beyond.

The structure was commissioned in 1773 by John Stackhouse, who named it after his wife Susanna Acton. He used it as both a residence and a base for his marine biology work during the late 18th century.

The grounds show where John Stackhouse worked with seaweed species, conducting research that became important to marine studies of his time. The old tanks used for his scientific work still remain in the gardens as traces of this scholarly past.

The property sits on elevated ground with clear views across the bay, making it easy to spot and approach. Note that the building has been converted into luxury apartments and is not open for interior viewing.

A tenant farmer named John Carter, locally called the King of Prussia, used the property as a smuggling base with rumored secret passages to a nearby cove. This link to illicit coastal trade adds another layer to the site's past beyond its scientific legacy.

Location: Perranuthnoe

GPS coordinates: 50.10550,-5.42557

Latest update: December 9, 2025 12:24