The Castle can be visited
Chastleton House

In Chastleton, Oxfordshire, England, is Chastleton House, a Jacobean country house. It is exceptionally well preserved, having undergone few modernizations over centuries, offering a glimpse into 17th-century life.
History+
The estate was constructed between 1607 and 1612 for the lawyer Walter Jones, who acquired the land in 1604 from Robert Catesby, the mastermind behind the Gunpowder Plot. Yellow Cotswold stone was used for its construction, and the house was built around a narrow courtyard, the Dairy Court. A unique feature is its integration into the village, meaning typical estate facilities were not present on the property.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: Colin Jackson
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 51.9597, -1.6401