To be privately owned
The Castle can be visited
Chillingham Castle

Chillingham Castle in Northumberland, England, is a castle whose origins lie in a medieval fortification. It is one of only two quadrangular castles in the region and has hosted royal visitors.
History+
The origins of the current castle trace back to a 12th-century Pele Tower, which served to secure the Anglo-Scottish border. In 1255, this structure hosted King Henry III. After an attack by Scottish troops around 1296/97, the property passed to Sir Thomas Heton, who received royal permission in 1344 to fortify the site. By 1348, it was expanded into a quadrangular complex with four corner towers. In the 16th century, following damage from a siege during the Pilgrimage of Grace, further alterations were made, including the construction of the southeast wing. King James I visited the castle in 1603 on his way to his coronation, which led to a redesign of the north facade.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 55.5259, -1.9043