To be privately owned
Fetteresso Castle

West of Stonehaven in Aberdeenshire, Fetteresso Castle rises. Originally a 14th-century keep, it has been transformed and expanded multiple times.
History+
The origins of the estate date back to the Strachans, before it passed to the Earls Marischal (Clan Keith) in the 14th century through marriage. This family, who also owned the nearby Dunnottar Castle, erected a stone keep on the site. In the 17th century, the building was expanded and acquired a large dovecote. Later, the Duff family took over the estate and carried out further alterations.
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: 56.9603, -2.2605